The road narrowed and grew shrubby as Andrew, Maddie (a graduate student at OSU) and I pulled up, looking for a place to park. Just behind us was the rest of the team in a second vehicle—Charles, another experienced member of the crew, at the helm.
“This one is very steep,” said Andrew with a grin. “We are going to challenge some of them [crew members].”
We were at Site number 93. The area had been sampled for fire scars on the opposite side of the road already. The plan today was to focus on setting up a plot and gathering forest development data which mainly involves coring trees.
Forest development, Andrew explains, is the history of how a forest changes over time. By gathering plot data and coring trees, he hopes to understand the different development trajectories a forest might undergo in relation to its disturbance history.
Fire Record
The fire record for the site showed fires in 1759, 1836, 1844, and 1883. But you wouldn’t know it from looking at it. The trees at this site were much larger and a good deal older than the forest we had sampled earlier in the day.
The fires, Andrew predicted, must have been low severity with low tree mortality since there are so many older living trees at the site. The oldest of the trees are over 800 years old, established in 1190, possibly following a stand-replacing fire.
“Now when we core the site,” said Andrew, “It will be interesting to see if we find cohorts of hemlock and cedar related to these fires [in the 1800s] because presumably they come in because of gaps or openings.”
Plotting a Plot
After gathering all of the necessary equipment, the crew, Andrew and I headed down through a thicket of young conifers that lined the road. The slope was steep as we navigated our way over and around downed logs and branches. Eventually, we reach the ancient forest and what would be our plot center.
Andrew’s plot design follows the same format as the Forest Inventory Analysis Program of the U.S. Forest Service—with three circular plots that branch out at 120 angles from a central plot (each with a radius of 58.9 feet) and smaller subplots and microplots inside these.
Andrew staked out the center of plot one. He chose the site in hopes of capturing multiple cohorts of trees, including a large old-growth Douglas-fir that sat just downhill of the center.
While he gathered some basic plot data, he set most of his crew to work on coring trees.
Growth Rings
Gathering core samples from all the trees in the plot is both the most time-consuming and important part of the plot data Andrew’s crew collects. Each core is carefully packaged and carried back to the lab for closer analysis.
Cores can tell you a lot of things about trees. The size of the rings tells you about growing conditions, while the number of rings tells you about the age of each tree and when it was established.
Charles and some of the crew stayed nearby coring some of the smaller trees on the uphill slope. Maddy and one other crew member took a stab at the behemoth below.
Coring Efforts
I sat with Charles for a while to try and learn the secret to getting the perfect core. Charles was coring a hemlock tree—a species notorious for being rotten on the inside. The bit screeched as he rotated the handle.
“As a general rule, if a tree is leaning the pith should be away from the lean,” Charles explained. “I chose the side that is kind of oval. I want to core into the shortest side of it… to core the shortest distance.”
Charles originally studied the Classic Period in school before returning to graduate school to study forests—something he had wanted to do for years. He explained enthusiastically how the field of forest ecology has placed a greater emphasis on humans as part of the ecosystems in recent years. A change for the better. The borer clicked as he talked.
Before long, Charles reached the center and stopped coring. He rotated the handle counterclockwise, breaking the connection between the core and tree, and gently removed it on a thin metal spoon. Unfortunately, there were tiny holes in the wood indicating rot.
“I might try a few more turns,” he said.
Persistence
As Charles continued coring his hemlock, I dropped down to check out what progress was being made on the old-growth Douglas-fir at the bottom of the hill. There was likely 800 years or so of rings to get through. I couldn’t imagine the effort it would take.
The team had just extracted a couple of massive pieces of core from the tree and laid them down on a nearby log. They looked pretty good to me, but Maddy wasn’t satisfied. The core was still short of the pith.
They tried a new angle and took turns spinning the bright blue handle. Gloves were a must-have for this line of work. And work it was. Maddy and her partner would spend the remaining part of the day attempting to get a quality sample from the tree.
Old Growth
With the creaking and squeaking of borers in the background, I decided to take a little hike around the forest plot. I wanted to get a different perspective of the forest and see if I could get a view of some of the old growth treetops.
When we first arrived at the site earlier in the day, Andrew was quick to point out that despite their size, most of the trees downhill from us were not old growth. Most of the trees we were able to see from the road still had a tapered top, having not reached full height or had time to flatten out.
In fact, most of the trees were probably about 260 years old—middle-aged for a tree—establishing after the 1759 fire.
“A 500-year-old tree will be really wide at the top,” Andrew explained, “and will have wide branches…”
In short, a flat-topped tree is an old growth tree.
Balancing near a log, I took a picture of a couple gnarly looking old growth trees and their heavily branched tops.
Old Assumptions
Work continued under the tall canopy. There were a lot more trees to core and measure.
As the crew worked, Andrew told me that the data we were collecting that day might also be used to test an old assumption about old growth trees.
“One of the assumptions about old growth forest is that it has no net change in biomass,” Andrew explained. “Whatever is dying is being balanced by what is growing.”
Old growth is sometimes romanticized as a stable, unchanging system. This may be true, but as far as Andrew is concerned there is a lack of evidence to say one way or the other. Based on careful reconstructions of the history of old-forests it seems more likely that they are always changing. Sometimes change is quick, like after fires or other disturbances, and at other times slow, at an imperceptible pace for our relatively short lifetime.
“Coring all these trees, we can quantify basal area increment over time,” said Andrew. Basically, you take the width of the rings and diameter of the tree to determine the volume of wood added each year.
This sort of data could answer a myriad of questions:
Does biomass increase or decrease in these old growth stands? Or, is the answer, it depends? How quickly are the younger cohorts replacing older slower growing trees and trees that have died? Where is the stand headed in terms of what types of trees and their structure?
Only time and an increment borer will tell.
Other Measures
Of course, there is a lot more data to collect than just taking cores. For each tree in the plot, DBH (diameter at breast height), height, species, and condition are recorded. Then, there is also a host of other measurements, like slope and aspect of the plot.
As I returned from my romp through the forest, I caught Andrew taking another measurement—woody debris.
Curious, I asked what he hoped to learn from tracking the downed wood in the plot.
First, he explained that it can relate to disturbance history as you compare what is on the ground with what material is consumed.
“Different development histories produce different woody debris,” he suggested.
“Honestly,” he added, “I don’t know how it will turn out.” However, if some sort of pattern does emerge in the data, by using the same protocols as FIA, it opens up possibilities for access to an even larger data set.
Back Again Tomorrow
It was late afternoon when Andrew’s crew wrapped up for the day. They probably would have stayed out even longer if I didn’t need to get home.
On the drive back to my car we chatted about all sorts of things—family members, hiking and climbing, and of course research.
Andrew and his team are not done. They will be back tomorrow. And probably the day after.
How does a forest grow?
In a million different ways.
Ask Andrew and his crew—they have all sorts of theories to test.
Andrew Merschel is an ORISE postdoctoral fellow working with the USFS PNW Research Station and he leads the tree ring lab at Oregon State University. Andrew uses tree rings to develop a shared understanding of how different forest ecosystems function over time. He is particularly interested in how disturbances (mostly fire) and forest management have shaped and will continue to shape forest ecosystems in the Pacific Northwest. Andrew lives with his family (Vanessa, Aldo, and Sawyer) in Corvallis, Oregon and they enjoy a mixture of fishing, hiking, wildlife ecology, and chainsaw repair in their spare time.
We often think of forests as static collections of trees, along with some shrubs, ferns, fungi, and other “foresty” organisms.
But forests are more than an array of cool critters and plant life. They are dynamic ecosystems that are constantly changing. Sometimes dramatically. As a result, there are times a forest may not look much like a forest at all.
Storms, pests and disease, landslides, and floods are parts of a forest ecosystem—interacting with the organisms that reside there and shaping forest development. Disturbances, such as these, are not only natural, but essential to many forest species—sending forests through complex paths of community change.
In Pacific Northwest forests, fires are an especially important example of these essential forces of disturbance. Forests in the Pacific Northwest evolved with fire and have adapted to the presence of fire on the landscape in a variety of ways.
Andrew Merchel, a dendroecologist from Oregon State University, knows the importance of forest fire to the region all too well. For the past several years, Andrew has been studying Pacific Northwest forests to better understand the patterns in fire frequency and, more recently, how these patterns might ultimately influence forest development.
I was fortunate to get invited along with his crew to a couple of his field sites this summer to see their research in action.
The Long Road to Site 87
It was a warm, sunny morning as I waited for Andrew at our designated pullout. I was parked just off the Santaim Hwy near Longbow Camp. Standing along the road, I passed the time watching the South Santiam River’s ripples catch the light and flash white below me.
Soon, Andrew arrived with his crew of young students, and we headed out to what would be the first of two sites.
As we traveled down the narrow, overgrown forest service roads, Andrew told me a bit about the site.
He explained that the site has had two relatively recent mixed-severity fires—one in 1848 and one in 1868, but before that, the only other fire they found evidence of was in 1535.”
“So, we had a fire a really long time ago, and three hundred or so years without fire,” Andrew emphasized, “and then two fires in the 1800s.”
As we got nearer to “site 87”, Andrew pointed out patches of thinning that had been done around the middle-aged Douglas-fir—an unusually recent occurrence on national forest land for the time—but helpful to us in our fieldwork for the day.
Records in the Rings
And then we were there—site 87. It was time to get to work. Andrew’s field crew made up of college students headed to collect forest development data on one side of the road, while Andrew and I went in search of the perfect stump on the opposite side.
As mentioned earlier, Andrew is a dendroecologist—which basically means he uses tree growth rings to better understand how forest ecosystems have changed over time. As part of that research, Andrew has been using crosscuts from dead trees and stumps to reconstruct fire records for a variety of forests in the West.
The tree rings on each crosscut provide a record of time that can be compared with other crosscut tree records to establish a timeline that goes beyond the lifespan of one tree.
Dendrochronologists can date each annual ring sampled from crosscuts even if a sample is collected from a snag or log that has been dead for centuries.
They date annual rings with a technique called cross-dating, which uses the sensitivity of annual tree rings to climate. Hot, dry years result in thin rings with narrow latewood and moist years result in years with wide rings with thick latewood in the Pacific Northwest.
Each decade has a unique pattern of thin and thick years that can be used like a fingerprint to precisely match a series of tree rings to the exact calendar years when they grew on the tree.
In this way, tree-ring records tell you a lot about the environmental conditions of each forest, including climate, over the recorded years. Most importantly for Andrew’s research, the rings also record fires as scars in the tree rings—providing information about the year, season, frequency, size, and sometimes severity of fires that occurred outside of modern records.
More Frequent
Research at the Forest Service’s PNW Research Station and the tree ring lab at Oregon State University has really shed light on the frequency of fire in Westside forests.
Before, ecologists thought that westside forests experienced fire as a function of lightning; and that fire was historically infrequent in much of the western Cascades and Oregon Coast Range—with forests going 100s of years between fires.
Now, hundreds of fire scars collected from dead trees have shown there are many ways fire exists in westside forests. Fire regimes (patterns of fire) are variable in frequency and in how they shaped forest conditions over time. For example, some westside forests record fire in nearly every decade, while others go centuries without fire. The role of fire historically varied with forest age, Indigenous burning, lightning, topography, and microclimate.
Searching for Scars
Chainsaw in hand, Andrew and I headed down the road and trampled our way uphill through the underbrush to check out some of the thinned areas for stumps to cut into. The goal is to find stumps that show fire scars—a blackened resinous area along a ring.
Andrew and his crew had already sampled the area, but he was hoping to get more samples from older trees. Looking at the age classes of trees in the forest, Andrew suspects there may have been another large fire in the 1820s yet to be discovered.
Not all Stumps are Like the Others
“There are clues about which stumps to cut into,” Andrew explained as we carefully picked our way over the bramble and down woody material. “Trees that scar when they are young, for example, will often scar again with the next fire.”
Oddly shaped stumps that are oblong tend to be good candidates. And of course, the stump needs to be solid without too much decay.
Another factor that affects scarring is that each tree species has its own resistance to scaring and the ability to preserve long records of past fires.
“Many Douglas-fir are not good recorders of historical fires,” Andrew remarked “The initial burn needs to be severe enough to form a first scar on a tree before it develops thick bark that prevents fire damage and the formation of a fire scar.”
Andrew leaned over one large stump and wiped away the smut that had accumulated on top of it with a brush with metal bristles.
“You can see an injury right there,” he said pointing to a white resin-filled gap between a couple of growth rings—a scab around the wound. “That looks like mechanical damage,” and probably not a fire scar, he concluded. Mechanical scars often go across rings, while fire scars form neatly along a single row of cells.
The search continued.
Making the Cut
We moved out of the thinned area and into the denser forest for a bit, looking for promising-looking stumps.
Soon we came across another with sampling potential.
“There is some rock-solid wood right there,” he remarked as he examined the stump—perhaps the product of resin released as the tree scarred.
It was time to make some cuts. Andrew and I put on our earplugs, and he began slicing horizontally through the stump several inches below the original cut. The whorl of the chainsaw and fine woody dust filled the air space.
It was over in just a few minutes.
Andrew removed the top he cut off and began sweeping away at the newly cut surface.
Nothing.
Just a few old branch whorls. No scars.
How to Scar a Tree
The fact of the matter is that trees don’t always scar.
Contrary to what you might think, fire scars form from heat, not flames.
“It is heat transmitting through the bark for a long enough period of time to kill the cambium locally,” explained Andrew. “It is more burn residence time and the ability to transmit heat for long enough that records the fire.”
Perhaps for this reason, if a tree scars when it is young, it will often continue to scar on the same line. They also tend to occur really low on the trunk near the ground where heat is transmitted to the tree bole from surface fuels.
Patterns of Variability
As we searched for another crosscut stump to sample, I asked Andrew to tell me more about his research findings. After all, this was not his first rodeo. Andrew and his team, at the time, had sampled up to 50 sites in Westside forest with 15-20 cross-sections from each one.
Yet, despite all the sampling, it was still difficult for Andrew to identify any environmental patterns.
“We don’t have enough to relate patterns of fire to different environmental settings still,” says Andrew with a sigh, “because there is so much variability.”
Consistently Inconsistent
However, Andrew admits there are some consistencies.
For example, low-elevation sites near major rivers, like the McKenzie and Clackamas, that are hotter and dryer tend to have more frequent fires. These also may be sites where Indigenous People used fire stewardship to produce vital cultural resources.
“Some sites are shocking—the amount of fire they have.”
On the flip side, there are higher elevation sites in the Silver Fir Zone, like Gordon Lakes, where fire is very infrequent. These places will record one high-severity burn, followed by one or two reburns, and then go more than a century without fire. Rinse and repeat.
It is at mid-elevation around 3,000 feet where it gets really challenging to predict.
The hope is to eventually look at the variation in topography, elevation, and other site factors in combination with fire histories to try and understand how forests develop in different ways based on their specific context.
Catface
Andrew and I moved back into the open with fewer trees and shrubby underbrush.
“Come on guys,” he says, leading the charge. “Where are the fire scars?”
As we search, we come across a burnt-out western redcedar with a charred opening in the lower trunk—a catface. A catface forms when the cambium on the tree is killed by fire, and in the next 10 or 15 years the bark falls off, leaving the tree susceptible to future fires.
“The earlier scars are burnt off by the later scars in there,” Andrew explains.
Cedars are interesting trees in fire. They get consumed by fire a lot.
“Cedars really do chimney,” explains Andrew, “Fire gets in there and burns them out on the inside.”
At the same time, “It doesn’t necessarily die,” said Andrew, “or rot” for that matter—instead cedars tend to stand as ghosts of fires past.
Fool Me Again
The stumps were easier to spot in the more open forest and Andrew found a couple more promising candidates. He was really hoping to find an older stump that might provide evidence of a 1759 fire he was fairly certain had occurred.
The chainsaw ablaze, Andrew sliced into another stump and then another, but to no avail.
One of the stumps was massive and took a lot of effort and some careful wedging to remove the cut surface. He cut a couple of cross-sections from the large stump.
“This one is going to frustrate us,” he declared before making this final attempt.
Unfortunately, it ended in sweat and sawdust, but luckily no tears.
Is it Severe?
At this point, we were low on gas and Andrew decided it would be best to start heading back down to the road to meet up with the crew.
As we made our way through the salal, ferns, and other shrubby species—a product of the thinning that occurred here—I asked Andrew about how fire severity fits into his research.
Fire severity is a measure of the magnitude of the immediate impacts of fire on the vegetation and living soil. In forest ecology, it is typically based on tree mortality—about 0-30% tree mortality for low severity, 30-70% mortality for moderate severity, and anything above that is high severity.
“Anything killing the fire-resistant trees is moderate [or high] to me,” Andrew suggested.
When it comes to fire severity, like frequency, Andrew has found that it too is not so easy to predict.
“I would agree that 2020 fires are nothing new,” explained Andrew, “We have always had big blowups, but we are missing fire events outside of these conditions all over the West Cascades that poke holes and do very different types of burning.”
In other words, though large high-severity fires do occur in the West, it would be a mistake to forget that there are many other types of fires that have shaped this forest type historically—fires that vary in both frequency and severity.
These differences in fire severity also occur on a much finer scale, according to Andrew.
“Here is an old-growth tree next to an early seral shrub,” he illustrated, “and they exist right next to each other—and that is normal.”
It is patchy. And that matters because that patchiness increases variety and biodiversity.
Forest Development Implications
Andrew told me about a paper out of Oregon State University by Chris Dunn that looked at the implications of fire severity for forest development in the Willamette and Umpqua National Forests.
In general, Dunn found that the severity of fire results in very different trajectories of forest development.
A low-severity fire may not result in a new cohort of trees, or it will result in shade-tolerant species including western hemlock developing on the site. In a high-severity fire, grasses and shrubs will make up the post-fire community with Douglas-fir the primary cohort of trees able to establish.
Then, there is moderate severity. This is where it gets interesting. It is in moderately burned forests that you can end up with the most biodiversity post-fire—with sites that have up to 17 different tree species established after fire in Southern Oregon. Having both canopy gaps and live trees remaining post-fire allows for greater variability in the forest community as different species find their ecological niche.
“One thing this project is going to do is we are going to core all these hemlocks and true firs and see if they actually link to fire,” explained Andrew, referring to the coring work his field crew is working on. “If they do, then I think we will interpret that low-severity fire was really important to the development of these species in westside forests.”
Forest Management Implications
Andrew spoke strongly about what this means in terms of forest management. If fire is variable, the way we manage the structure of forests should also be variable.
“We can’t just do one thing in plantations where we are trying to restore heterogeneity and biodiversity,” said Andrew. “We should be doing everything from removing 10% of trees to 90% of trees. That is historically probably what happened—creating a lot of variability.”
The result would be real; and probably pretty messy.
“Instead of distinct edges, you would have a constant mosaic,” Andrew described.
What we are doing now in plantation settings is not natural.
“The plantation is completely artificial… cut at 40 years or so and planted uniformly at a high density—this is not one of the development trajectories. It is not mimicking historical disturbance processes or stand development.” Looking ahead, the ecosystem that develops from a plantation will be much different than the ecosystem it replaced.
Making the Cut
We were just about back to the road when Andrew noticed another stump that had been cut the last time he visited. Having not found any stumps with fire scars yet, he led me over to this one—hopeful that I might observe the scarring up close.
After wiping away needles and other debris, we got down to stump level. There we could see two scars—one from the 1868 fire sitting just above the other from 1848. “Which is sort of classic,” remarked Andrew, as far as fire scars go.
The scars showed up as what looked like a break in the annual rings (cambial necrosis) with resin separating the blackened tissue from the wood wound put down during the healing process.
Much of the cut area was also covered with a white rot—the forest ecosystem eager to restart the decay process.
Back on the Road
Soon we were back on the road to meet up with the rest of the field crew. After checking out one last stump on the opposite side of the road, we all piled back in the vehicles for another long twisty ride to field site number two for the day.
Forest ecosystems are dynamic. But they change on timescales that are often outside of human experience. Understanding fire as an agent of change in our forests requires long-range data sets, like what Andrew has tirelessly been collecting—helping fill in our knowledge gaps.
We may not have succeeded in finding a fire-scarred tree that day, but I am grateful to have experienced the forest through Andrew’s eyes—to understand its wonderful complexity and the secrets it retains deep beneath the bark
Andrew Merschel is an ORISE postdoctoral fellow working with the USFS PNW Research Station and he leads the tree ring lab at Oregon State University. Andrew uses tree rings to develop a shared understanding of how different forest ecosystems function over time. He is particularly interested in how disturbances (mostly fire) and forest management have shaped and will continue to shape forest ecosystems in the Pacific Northwest. Andrew lives with his family (Vanessa, Aldo, and Sawyer) in Corvallis, Oregon and they enjoy a mixture of fishing, hiking, wildlife ecology, and chainsaw repair in their spare time.
What do you get when you cross a geologist with a computer scientist? Easy, a Schmitty Tompson. Part rock nerd and part computer programmer, Schmitty is passionate about reconstructing Earth’s climate history one computer model at a time. Lucky for me, Schmitty is also equally passionate about communicating science with the public, and graciously agreed to meet me on the Oregon Coast for a hike and chat.
Walk and Talk
It was overcast and a bit windy when I pulled into the Cape Perpetua Visitor Center Parking lot, Schmitty and I’s agreed upon meeting place. Schmitty was all smiles and pleasantries, and we soon were on the trail and introductions were underway.
Schmitty is a 5-year PhD student at Oregon State University where they have been studying ice ages (a topic we would spend a lot more time on later), but perhaps might be better described as a Jack-of-all-trades.
“I need to know a little about a lot of different things,” explained Schmitty as we headed down the paved path from the visitor center that leads to tide pools and Spouting Horn. “I learned about glaciers and ice sheets. And I study ocean physics and what the interior of the Earth looks like… It is very interdisciplinary.”
As mentioned earlier, Schmitty is also very interested in public outreach.
“I am happy to do my best to talk about anything else about Earth Science!”
A Rocky Start
Schmitty’s love for science was born from an early age, but it wasn’t until an 8th-grade summer camp where they took a canoe trip into the boundary waters of Minnesota that they realized they could make it a career.
“The person leading the trip had just graduated with a degree in geology and she was telling us about the rocks all around us and I was so fascinated,” described Schmitty. “She was blowing my mind!”
It was during that trip that Schmitty decided that they were going to be a geologist and announced it for the entire camp to hear.
Still, in high school Schmitty found themselves leaning toward a career in computer science. It wasn’t until they were in college that they were able to make the connection back to geology.
“I had a really amazing mentor,” said Schmitty.
Basalt Pools
By this time, Schmitty and I had reached the tidepools and the rough, jagged rocks that hold them.
Cape Perpetua’s rocks are part of the Yachats Basalts that erupted some 37 million years ago along the edge of the coastline of North America.
“They [basalts] can form when a hot spot or plume of magma bubbles up from the earth’s crust and creates this really big active volcanic center,” explained Schmitty.
Basalt also comes in a variety of patterns—sometimes blocky, other times craggy, other times smooth.
Much of what we saw in the tidepools was blocky or columnar. We also saw basalt rock with small vesicles—aptly named vesicular basalt—that form from air pockets in the lava as it cools.
Vesicular basalt near the tidepools
Fractionation
Basalts are not the only type of volcanic rock, however.
“There is a scale of what these rocks are made of,” Schmitty explained. “It starts with ultramafic that are really high in magnesium and iron; low in silica.”
Then there is mafic rock—these are your basalts, and what the ocean crust is made of.
Looking out at the vast ocean, I tried to imagine this rock lying somewhere below the weight of the ocean and accumulating sediments.
Basalt is also incredibly common “because if forms in so many situations.” However, not all rock reaches the surface as mafic rock.
“As magma moves up it cools,” explained Schmitty, “the squishy minerals are mixed, but they cool at different temperatures and ‘fall out’ as they cool.”
This is how more “evolved” volcanic rocks are formed. This process of magma evolving as it rises through the mantle is called “fractionation,” and is responsible for the formation of felsic rocks, like rhyolite, that are higher in silica.”
Schmitty described the process of mantle rising and carrying up magma towards the surface as a process like a pot of water boiling—it is the rising, cooling, and falling that keep plate tectonics and associated processes like volcanism going on the Earth.
“There is a whole world underneath us and we will never see it,” Schmitty observed.
Basalt rocks form the tidepools above.
Terraces
After poking around the rocks, a bit longer, we continued on the trail towards spouting horn. Looking back from this vantage point, Schmitty noted a small exposure near the shoreline.
“You can see different layers,” they noted. Cobbles were part of the strata—perhaps an old creek bed, for instance.
Exposures like these are not uncommon along the coast. In fact, as the land has been lifted upwards, there are many places along the Oregon Coast where these exposures exist.
“Sometimes you can get sort of stairsteps,” Schmitty described. “These flat stairsteps are old beaches.”
The overall stair-step landform made up of “old beaches” is called a terrace. Each step was an ancient coastline that was moved “up” by plate tectonics.
A layer of rounded cobble suggests the location of an old riverbed
Standing on the Shoulders
“Terraces are part of my thesis,” Schmitty exclaimed. “I specifically study sea level rise.”
According to Schmitty, there are a lot of terraces along the Oregon Coast that have been documented and provide an important data set for their research. Combined with other data sets, like those from terraces and reefs along the Atlantic Coastal Plain and Caribbean, Schmitty had what they needed for their thesis.
“Terraces and coral reefs form where the land meets the Ocean,” they explained. “We call these sea-level indicators because they are not in contact with the ocean, but we know they formed at sea level.”
“Why I love these local records they capture these patterns really well,” they continued. “You get these crazy patterns in the indicators. You capture the dynamics going on. It’s like getting an action shot.”
Schmitty’s research involved digging through tons of old papers and records from researchers of the past to try and put together a history of our changing oceans.
They asked me, “Have you heard the phrase, ‘standing on the shoulders of giants?’”
I nodded.
“I stand on the shoulders of field scientists,” Schmitty offered the appropriate accolades. “Awesome people who have spent thousands of hours out there.”
Rise and Fall
The trail paralleled the coastline and its rocky shore. We watched the waves crashing into the basalt formations as we walked. Was the sea level today very different than a thousand years ago? What about 100,000? Or even a million?
Sea level indicators tell the story of change, but the question remains—why has sea level changed?
According to Schmitty, there are a lot of contributing factors from changes in the Earth’s position relative to the sun, as well as the amount of water locked up in ice during any given period.
Fortunately, these changes follow predictable cycles.
“Over the last 2.5 million years, Earth has been descending in and out of ice ages—the more technical term is glacial cycle,” Schmitty explained. “It cools down slowly until it reaches really cold conditions, and we have massive ice sheets covering a lot of the planet…It takes 100,000 years to cool down. Then very quickly it warms up, ice sheets will melt, and it will be like that for a couple of 1000 years.”
The Sun and Earth
What triggers these changes? In short, how the Earth is oriented towards the sun.
“The way the Earth orbits the sun is not constant,” Schmitty clarified. “It is not circular, and it changes over time. How much the Earth is tilted also changes.”
The Earth follows predictable cycles—“100,000 years for Earth’s orbit to change shape, 40,000 years for deep tilt, and 20,000 years for which way it is tilting.”
It is the confluence of all of these cycles that help scientists make predictions about sea level.
Interglacial
These predictable cycles are responsible for glacial periods, like the one that occurred about 125,000 years ago—commonly referred to as the Ice Age. However, they are also responsible for the many cooling and warming periods that occur between “ice ages”—a time period known as an interglacial period.
During an interglacial period, as Schmitty described it—“it cools, warms up a bit, cools, and warms up a bit.” And it is “one of these little warm-up-a-bits” that Schmitty studies.
What’s in a Name
“The one I study happened 80,000 years ago,” Schmitty recounted. “If you want to use the fancy word it is Marine Isotope Stage 5a.”
Say what? I asked Schmitty to decode.
First off, the word isotope just refers to the different varieties of atoms of a given element—for example, carbon-14 vs. carbon-16. The isotopes of an element behave a bit differently depending on how stable or radioactive they are and move differently through the atmosphere and oceans because of their differences in weight. For this reason, the ratio of certain isotopes that exist in certain climate proxies, like those found in deep ocean sediment cores, can tell you something about the climate of the past.
“The one that is relevant to me is oxygen,” explained Schmitty. “It tells you how the temperature changes and how much ice there was on the planet. Someone graphed it a long time ago and it is the peaks and valleys that represent the different isotope stages.”
So, essentially the “little warm up” that Schmitty is studying shows up as a little peak on a graph where the oxygen-18 in proxies were lower and the temperatures a little bit warmer some 80,000 years ago.
Variable
We continued toward Spouting Horn, moving down nearer the rocky shelves of basalt rocks. As we walked, I noticed how some of the basalt rock looked different in color and texture than the surrounding rock. This can occur when new rock is formed within existing rocks creating a geological feature known as a dike.
Interestingly, newly formed rocks are often stronger and more resistant to weathering compared to the rocks that surround them. The results are dramatic and beautiful.
Rocks are not the only thing that is variable. Turns out, sea level is also variable, not only throughout time but also geography.
“It is not just ocean rising,” said Schmitty, “part of it is tectonic plates moving up or down.”
They explained how most people imagine the world ocean like a bathtub with water flowing in through the spout and out through a drain, but it is far more complicated than that.
“One of my favorite things to tell people is that when an ice sheet melts, sea level is going to rise more away from the ice sheet than close to the ice sheet,” said Schmitty.
This may seem counterintuitive at first, but Schmitty explains it, “Ice sheets are really big,” so as they melt the loss of mass reduces the ice sheets’ gravitational pull of water allowing the water to move and disperse away from the ice sheet. Additionally, the weight of the ice sheet also lessens, allowing the ground underneath and around the ice sheet to rise as the pressure is reduced on the Earth’s mantle below.
“This is why I love these local records,” Schmitty exclaimed, they capture these patterns really well! You capture the dynamics going on. It is like an action shot.”
Bringing it Together
Schmitty and I finally made it down to Spouting Horn and watched the waves slosh up against the rocks, occasionally taking to the air through the narrow gap at the top of a sea cave. We didn’t stay long at Spouting Horn. The wind and cool, dampness of the day made it hard to hear or stay still too long. So, we about-faced and headed to the other end of the trail.
As we went, Schmitty told me about the other part of their work—the mathematical part—modeling.
All the local records that Schmitty spent hours upon hours researching needed a model to pull it all together.
“There is a limit to what it [the local records] can tell us,” said Schmitty. Yes, you can identify some patterns in the data, but a model brings context to the records.
“There are things that a model can tell me that geological records can’t tell me,” Schmitty continued. The model uses scientific laws and facts about the physical universe, along with observable phenomena to make predictions about the past.
Specifically, in Schmitty’s case, the model they are working with spits out a slideshow of “what all the past ice sheets looked like and spits out maps of what past sea level looked like around the globe.”
Pretty cool, right?
A Dirty Word
Yet, the word “model” is often considered a dirty word in science writing (whoops).
“Never use the word model if you can avoid it,” Schmitty said was the advice they got regarding science communication.
This advice makes sense when you consider how difficult it is to explain modeling, but on the other hand, maybe that is just the reason it needs to be talked about.
“I think the most underutilized tool is other modelers talking about models,” they continued. “I think I would love to see more modelers talking.”
A Model Model
Schmitty and I were heading north along the trail now hoping to reach Thor’s Well but we hit a roadblock. The trail was closed, and we needed to turn around. But before we high-tailed it back to the parking lot, we stopped at a small turnout in the trail.
Here, I asked Schmitty to elaborate further on modeling. Shying away from the word model, what other words might you use to describe what this thing is?
“I have a computer program,” they begin, but that seems a bit complex too. “I have a lot of code on my computer, and it does math. You have these equations to figure this thing out. The equation does the math, and you get new information out…. I use it to do other science.”
Okay, simpler.
“I always think of it like rules,” I chimed in.
Schmitty agreed. “Yes, it is a set of instructions… I give it something to start with and it gives something out.”
That is what a computer model is in a sense—a model for what a model is.
A view of Devils Churn from the trail
The Future
We continued back to the parking lot and decided we would drive over to Devil’s Churn before we parted. We hopped into our vehicles, headed north a short distance, and parked.
Once out of the car, we walked over to a viewing area. Foam from Devil’s Churn floated by.
I asked Schmitty if there was anything I had missed in the interview so far. “What else needs to be said?”
“One question that usually comes up,” admitted Schmitty, “is Why should we care about this?”
A very good question. So, what is the answer?
“I am figuring out one piece of a larger puzzle for understanding global warming,” Schmitty began. “If we can put together a really good picture of how the planet changed in the past… that can help us look into the future.”
Schmitty is studying one little warming-up period. But by understanding how ice sheets and glaciers responded and how sea levels changed during that period, they are adding to the breadth of scientific knowledge about the relationship between temperature and changes in the cryosphere adding to the predictive power of the models that project into the future.
“Our present is the key to the past,” Schmitty clarified, “and the present is the key to the future.”
That is how geology works.
Schmitty Thompson is a PhD student in geology and computer science at Oregon State University where they study and model sea level changes during glacial cycles. They are passionate about science communication and getting people excited about geology, however, they want to engage with it. They hope to encourage budding scientists, especially those who are underrepresented in the scientific community, towards a career in science if that is what they are interested in.
Grab some binocs the next time you head out for a hike or walk—the birds are on the move. In spring and early summer, thousands of birds hit the skies for their biannual migration.
The Willamette Valley is part of the Pacific Flyway—a superhighway for bird migration. Birds travel from as far south as Patagonia, making their way north toward Alaska. For those that live, work, or play en route, viewing these birds is a delight of the season.
Josée Rousseau—an ecologist at the Cornell Lab of Ornithology —takes it a step further by tracking bird migration and the different habitats birds occupy. Ornithologist extraordinaire, I met Josée at Luckiamute Landing State Natural Area for a hike and interview. I figured, if anyone knows where the birds are at, it would be Josée.
Binoculars in hand, Josée and I met at the park entry road to begin our hike. It had been cool, breezy, and overcast and moisture hung in the air—not ideal conditions for looking for birds, but we remained optimistic as we started down the wide path. Besides, I had seen a group of turkey vultures on the road on the way in feeding on an animal carcass—was this a sign of good things to come or some bad juju?
Seeing Birds
However, almost immediately, we started seeing and hearing birds—first, a Song Sparrow trilling in the distance. Then moments later we spotted a bushtit nest hanging in the trees.
“The cool thing about them [bushtit],” Josée smiled, “is they are sort of a cooperative species.”
She explained how juvenile birds from a pair’s first clutch will sometimes “hang around” to help with a second clutch—creating these large family units. You don’t generally see Bushtit alone for this reason. Rather, these stout little gray birds flit about in energetic flocks.
“Another cool thing,” Josée added, “the male and female have different colored eyes. The males and the young have black eyes and the adult females’ eyes are yellowish.”
A Closer Look
We soon reached a junction where the road ended at a parking lot and the trail began. We headed right, following a line of trees and shrubs, including holly-leaved Oregon Grape.
I asked Josée to share a bit about her background, and as if one cue—an American Robin, with its distinct song, made an appearance perched in some nearby trees.
“Robin was the bird that got me into birds,” Josée explained. “I study birds, I love birds, “but I didn’t always like birds.”
She explained how she needed someone to teach her “to see birds” before she could appreciate them. To stop and look at birds—to look at their plumage, shape, and size, for example.
And for Josée, as commonplace as they are, the American Robin was the first bird she took the time to really observe and appreciate.
Robin sent out the occasional twittering song as we talked before it flew back among the trees.
As we continued down the muddy trail, heading toward the Willamette, Josée told me how she started her research studying urban birds in Montreal.
“Birds are amazing creatures with diverse habits and habitats,” said Josée. Even in a city environment, there are resources available that attract birds.
Just then a couple of small birds caught our attention as they danced among the branches of a small broadleaf tree along the forest edge. Josée grabbed her binocs.
At least one was a Yellow-rumped Warbler with black, white, and yellow plumage. A larger bird for a warbler, it reminded me of a chickadee in size. The others flew off before they could be identified.
Big Bird Data
Josée and I flew on down the trail as well, heading into the denser woods.
As we walked, Josée told me about her move to the west coast and Ph.D. work studying large-scale patterns in bird distribution and habitat.
She explained how her research looked at both the distribution of bird species across North America, as well as the habitats that each species selected in different regions and throughout its life cycle.
“I found there were actually differences!” exclaimed Josée—particularly when comparing across regions, but even across the lifecycle Josée found slight differences in habitat use.
Josée’s research relied heavily on large data sets, including banding data, breeding surveys, and ebird—a citizen science program.
“It allowed me to use big data to ask large-scale questions,” she explained. “It involved a lot of computer work,” she laughed.
Bird Banding
However, there is one way that Josée still gets out among the birds. She and her colleague, Joan Hagar, have a bird banding station set up in the park.
Bird banding is the process of temporarily capturing birds, usually with a mist net, so that scientists and volunteers can gather data on the birds.
“When you capture a bird, you can determine their age and sex; you can determine their health…” Josée explained, “You are getting information about survival and reproduction.”
All this information can then be used to better understand changes in bird populations.
Other tools, like ebird or other more general surveys, can tell you some information about abundance, but they can’t tell you why the abundance of a bird changes.
“They are complementary tools,” according to Josée. We need a variety of data sets to answer a variety of questions.
Restoring the Floodplain
As we rounded a bend in the trail, the Willamette River came into view through the trees. A few user trails led closer to its edge for a better view. We stuck to the main trail and entered a dense, shady conifer forest.
“This site is cool because it is along the Willamette River,” Josée said, “It is actually at the confluence of three rivers—the Luckiamute, the Santiam, and the Willamette.”
Luckiamute Landing State Natural Area has one of the largest remaining natural floodplain forests, according to Josée. Though previously cleared for agriculture, much of the site has since been restored to a more natural state through a succession of plantings.
“I think the first planting was around 2013,” said Josée. “They planted the whole west section. The last section, the middle part, was planted just last winter.”
In fact, one of the main purposes of the bird banding project is to see if the restoration is working.
“And is the restoration working?” I asked.
“Yes, yes, yes,” Josée responded. “We have five years of data to support it.”
Superlative Birds
We continued along the wide path, scrubby conifers surrounding us on both sides and the river hidden to our right, hoping to spot some birds among the trees.
I asked Josée what birds she had seen coming through her bird banding station at Luckiamute. Were there any that are especially common? Any rare or unique birds?
“Fifty-nine species,” Josée responded. That is the minimum number of songbird species that visit Luckiamute at some point during the year—some as migrants or breeders, others as year-round resident species.
“The most common is definitely the Swainson’s Thrush,” Josée continued. “They arrive in May and stay until September.”
Swainson’s Thrush is in the same family as the American Robin and has “amazing vocals,” according to Josée. However, they are not talkative birds after the breeding season and often go unnoticed for that reason.
So how does she know they are here? Mist nets of course! Another benefit of bird banding stations.
There were two birds that Josée said fit under the “whoa!” category.
First, she showed me a picture of a gorgeous, fluffy juvenile Saw-whet Owl. Those big yellow eyes! It was a surprise to catch in the net, as they hadn’t heard one here before.
Second, is the Red-eyed Vireo. A lovely little bird with an olive-colored complexion and red eyes as an adult.
“Not a species that is abundant in Oregon,” Josée explained, “we have caught maybe three to four.”
“They breed here in the gallery forest north,” she went on, “but during post-breeding, they come down into the shrubby area where there are berries, and that is when we catch them.”
Coniferous
We were nearing the end of the shaded coniferous forest. We passed what looked to me like a woodrat’s nest up in a tree and several piles of woody debris.
“They have flooding here,” Josée explained.
Before we exited the habitat, I asked Josée what birds might frequent the area we were walking in. What sort of birds like conifer forests like this?
Josée rattled off a few species—”chickadees, kinglets, Steller’s jay, a few species like that.”
Conifer forests provide shelter for birds but do not have as abundant food resources.
“Very soon we will get into the shrubs,” said Josée. “They have more birds because they have more insects. And they tend to have flowers and berries which attract fruit-eating birds.”
Gallery of the Giants
And she was right, soon we rounded a bend and soon we were face to face with a tall deciduous forest and a trail bordered by shrubs.
A sign offered some details about the forest and restoration process—which indeed started in 2013. We stopped at the sign for a moment and looked out on the gallery of what was mostly large Black Cottonwood with many Bigleaf trees in front of us.
I asked Josée what she thought the benefit of this habitat was to birds.
“Big trees,” she began, “There is more vertical habitat for one thing.”
She also mentioned the formation of snags in older forests which brings in woodpeckers, which create cavities that can be used by a variety of cavity-nesting birds.
“There is a lot of complexity in an older forest that you don’t get in a younger one. By having that vertical structure, these older trees, by having snags and dead wood—this adds a variety of habitats and resources that more species because they all use a different part of it,” explained Josée.”
Water Ways
Of course, different birds need different habitats. Many require old-growth forests, but others need young forests, grasslands, or some other habitat type.
“There is no good or bad habitat,” Josée reminded me. “Even cities aren’t necessarily bad habitats because there are some species that thrive in them.”
I asked Josée if there was any special benefit of being near water.
“We don’t have a lot of rain from June to September and birds rely on fruits and nuts to fatten up in the fall,” explained Josée. “So, these riparian corridors are very important for these birds to find food and be able to survive migration, at least for the west coast.”
Shrubby
We continued following a corridor of planted deciduous trees and shrubs—part of the restoration project.
Among the shrubs were osoberry, common snowberry, and red-flowering currant—all of which can provide food resources for different bird species.
“What is great about Luckiamute is they restored habitat by planting native species of plants, which is amazing to me,” Josée shared, “AND to the birds,” she added with a smile.
To better understand how birds are using these flowering plants as resources, Josée told me how they are providing data to a research project led by Carolyn Coyle, through sampling the beak of warblers they net for pollen. Each sample is tested to identify plant species the warblers visited.
Preliminary pollen testing last year showed promising results.
“Warblers used these flowers,” said Josée, “and other flowers in the park.”
The next phase of the project is to try and understand why.
Early Seral Station
Josée pulled off to the side of the trail toward a tree tied with bright pink flagging.
“See that little flag,” she proclaimed, “We have a bird banding net right here.”
As she headed into the brush, Josée explained the components of a banding station. Here is the gist–each station has about 10 12-meter-long nets that stand 2 meters high. The nets are put up during a collection day and checked frequently. Birds caught in the net are carried to a banding location where a federal Bird Banding Lab tag with a unique number is attached to their leg.
“And we are going to get age, sex, species of course, look at weight, wing length, and other measurements such as breeding condition, and release it,” said Josée.
We were standing at net 10—one of a total of 30 set up around the park. Net 10 is considered an early seral habitat station, though the forest was a lot thicker since last she visited—it had since been thinned.
Reasons
“Surveying these birds is not part of my regular job,” she explained but is done on a volunteer basis for three main reasons.
Besides, helping provide feedback on the restoration efforts (reason number one), the bird banding station offers young biologists training in the safe handling of birds and how to take accurate measurements.
And thirdly, “We are doing some research,” said Josée. “We are studying this area as a migration corridor.”
Migratory Path
“Do most birds fly in riparian corridors during migration?” I asked.
“We suspect that they do and that is what we are trying to find out,” Josée replied.
Joan Hagar, Josee’s colleague, did some surveys in 2014 and found some evidence to suggest birds were following the Willamette during migration. Essentially, she found the same birds visiting another banding station along the route, suggesting they were sticking to the water.
“So, another tool we are starting to take advantage of is MOTUS,” said Josée.
MOTUS is an international collaboration network that uses radio telemetry to track the movement of a variety of species including birds. Each bird is outfitted with a radio transmitter. Josée described it as looking like “a little backpack.” Then when a bird flies by a MOTUS station, the bird’s signal is picked up and recorded with a time stamp.
“Ankeny [Wildlife Refuge] just got a MOTUS station,” said Josée. Both Joan and she are hoping to see more come online along the Willamette.
Return to Sender
“Do you capture some of the same birds?” I questioned.
“We have caught the same Swanson’s thrush 3-4 years in a row in the same net!” was Josée’s enthusiastic response.
She explained how Swanson’s thrush migrate as far south as Bolivia and Argentina, only to return to the exact same spot they began—so exactly that they end up caught in the same mist net.
“They have migrated thousands of miles,” she was bubbling over with energy. “Image you were flying to Argentina every year!”
I’m impressed.
Indicators
By now the trail opened with a field to the left. We were almost back to our loop and the sky was starting to darken. I asked Joséee about her current research as we walked the final leg back to the loop junction.
“I’m a postdoc for the Cornell Lab of Ornithology,” said Josée. “And my project, which I think is really cool, is to see if we can use birds as an indicator of pollinators.”
As Josée explained, pollinators are declining at alarming rates, and at the same time, we have limited data on pollinators, so the extent of the problem is hard to nail down.
Josée’s project is designed to take advantage of the extensive data we have on birds to see if it correlates with the presence of native bee species.
“I am using eBird,” said Josée, “and publicly available bee data sets. I am using locations with both bird and bee data. There are only a few locations, maybe up to 4,000 in the eastern half of the U.S.”
The research is based on the premise that bees and some bird species use similar habitats and environments and are affected by similar land management practices.
“So, we can see if whenever some bird species are abundant, we have more bee species,” she explained.
Ultimately, Josée hopes that by using birds as indicators of bee richness, they can guide land management practices to improve bee conservation.
Spring Showers
Then, (almost suddenly) the leaves rustled, and the grey ominous clouds shifted in the sky, letting out a soft but thorough downpour.
Despite the change in weather, Josée heard a call out in the field next to us—a white-crowned sparrow. I could see it shifting in the grasses, a dark silhouette against an equally dreary backdrop.
Josée handed me her binoculars to see if I could get a better look, but the rain had dampened the eyepieces. It was like looking through a rain-soaked windshield with no wipers.
Grassland species
“What species would like this area?” I asked, as we moved swiftly back to the junction and road we walked up at the start of the hike.
As usual, Josée had an answer—“White-crowned Sparrow, Common Yellowthroat, Robins…”All of these birds use these open habitats.
However, the area was already in the process of change. If you looked more closely, small saplings were planted among the grasses that dominated the field.
“They planted last winter,” she said. “And as these little trees are growing, we are hoping to add nets here and monitor their impact on bird communities.”
Energy
We hurried our way back to the cars. The rain, only letting up a little. Not an ideal situation for looking for birds. They too were probably seeking shelter.
Back at the cars, I thanked Josée for meeting with me, but I couldn’t help but comment on her relentless energy. She was not shy about acknowledging that she is a go-getter.
It was fun talking to Josée. Like the birds she studies, she had figured out a way to successfully navigate through a career in science—and with gusto!
I have no doubt she could make the thousands of miles-long journey her birds take if she needed to.
Josée is a postdoctoral fellow at the Cornell Lab of Ornithology where she is studying the potential role of birds as indicators of pollinators.
Rushing water. A shushing breeze. Rustling leaves. Chattering wildlife. These are the sounds of a forest in the foothills of the Willamette Valley. Soft, tranquil, quiet. Or at least in winter.
The forest awakens in spring. As flowers stretch out their petals and leaves unfurl to catch the sunlight, the tranquil chatter of the forest turns into an all-out symphony of sounds. Like the string section in the orchestra, it is the birds that draw the most attention.
I have always enjoyed bird song but have not yet mastered their melodious rhythms. This spring I am determined to take a closer listen.
Fortunately, Joan Hagar, a research wildlife biologist with USGS, agreed to meet with me to talk birds in a local forest.
The Hike
Trailhead: 720 Gate at the end of Sulpher Springs Road
Distance: approximately 2 miles
Details: Limited parking at the end of a well-maintained gravel road. No fee for parking. No restrooms. Park at gate 720 gate and head up Road 720. Look for a right turn-off on a user trail that takes you back to the gate. Map of area available on OSU College of Forestry website.
Introductions
I met Joan on a cool spring afternoon. It was overcast, but not raining. Would the birds be out?
We didn’t take but a moment before heading up the trail which rose along a riparian corridor next to a rushing creek.
I asked Joan to tell me more about herself and her career.
“The focus of my career has been to help forest managers incorporate wildlife habitat into their management plans,” she explained as we walked. “Remind them that they can accommodate wildlife at the same time as they are meeting their other goals.”
More specifically, she is all about the birds. Joan has spent her career studying birds and other wildlife in the Pacific Northwest.
As Joan explained it, she was born with it.
“My dad was a wildlife biologist and taught me the birds,” she explained, “and being able to hear them and know what species you are hearing it is like understanding a foreign language.”
A skill she would prove multiple times on our walk, but at least for the moment, the forest was rather quiet.
Indicators
As we continued our gradual climb up the forested hillside, I asked Joan “Why birds?”
“Birds, it turns out, are really great indicators for management and environmental change,” explained Joan.
Many species are only suited for a particular habitat or forest type. If the environment changes, so does the bird community. As a master’s student, Joan explained, she was able to see this firsthand.
Joan studied the impact of forest thinning on bird communities.
“I am going to show that harvesting is bad for wildlife,” Joan’s early scientist idealistic self-had thought, but she was mistaken.
“I found out that when the canopy of these dense conifer stands opened up and allowed the understory to develop… that meant more productivity—more flowers, fruits, seeds, and insects,” said Joan.
In essence, thinning increases resources birds relied on and as a result bird diversity also increased as birds that were attracted to the more open habitat arrived.
“Disturbances aren’t a bad thing,” Joan concluded.
Of course, “that is a bird perspective,” said Joan. “Amphibians might feel differently.”
Why birds?
In addition to birds’ ability to respond so quickly and clearly to environmental change, there are many other reasons birds are useful biological indicators.
“Birds are everywhere,” said Joan. “And they are fun to watch.”
Joan tried studying amphibians early in her career but found it more difficult.
“You have to turn over a lot of logs to find them,” Joan explained, “and in doing so you have to destroy their habitat.”
(Turns out, Kermit is right—It ain’t easy being green.)
Birds, on the other hand, can be counted by sight and/or sound.
For more detailed demographic data, mist nests may be used to capture the birds temporarily to study them. By using a method called “mark-recapture,” even the abundance of birds may be calculated.
Riparian Resident Birds
Deciduous trees, like bigleaf maple and red alder, having still not leafed out, offered views down towards the water as we walked.
“So, what kinds of birds would you find here?” I asked.
“Usually there are a lot of birds here,” Joan responded and pointed out the chattering call of the Pacific Wren.
“They [Pacific Wrens] start nesting this time of year,” she continued; “they like a lot of dead wood—stumps, logs—and they love the riparian area because of all the trees that fall in and it is damp and moist.”
Pacific wren is a resident species in Oregon’s western forests, along with Spotted Towhee, Song Sparrows, Canada Jays, and Steller’s Jay.
Barred owls and Pygmy owls are also common residents found nesting in snags.
“I have long suspected a Pygmy Owl nesting near here,” said Joan.
Riparian Breeding Birds
“In a normal year we would be hearing warblers,” Joan continued as we rose above the creek.
Orange-crowned Warblers usually arrive in April, with Hermit Warblers arriving a few weeks later.
“They [Hermit Warblers] are really cool because they only breed along the west coast here—from the coast to the Cascade Mountains,” said Joan excitedly.
Hermit warblers are what Joan called “endemic breeders.” Traveling to Central America during the non-breeding period and returning to their narrow breeding range in Pacific Northwest forests.
“Pacific-slope Flycatcher,” Joan recalled is another riparian migrant. “I am usually starting to hear those this time of year.”
Pacific-slope Flycatchers are especially fond of forests and woodlands near waterways where the canopy is dominated by deciduous foliage—often nesting on the slopes of forested canyons.
“They love these riparian trees, like maples and ash,” Joan remarked. Here the flycatchers catch insects below the canopy.
Woodpeckers
Early spring is also a great time to see woodpeckers in Oregon’s Willamette Valley forests.
“Hairy woodpecker, Downy woodpecker, red-bellied sapsucker…” Joan rattled off some examples.
It is nesting season and woodpeckers are out scouring the woods for the perfect tree to build a nest in.
“Woodpeckers are primary cavity nesters,” Joan accounted.
Primary means that they excavate their own cavity, as opposed to secondary cavity-nesters, like chickadees, bluebirds, and wrens, that depend on woodpeckers to provide cavities.
“They do the excavation of the cavities because they have strong bills,” Joan explained.
“Woodpeckers are funny because they do a lot of excavating before they settle,” she continued. “The male goes around and makes a cavity, then the female checks it out and goes ‘eh’ and so he makes another cavity.”
This process continues for a while until the female is satisfied. Fortunately, the result is several new unoccupied cavities produced each nesting season. This is great news for secondary cavity nesters, like chickadees and nuthatches, who are soft-billed and reliant on finding a home in already existing cavities.
“They [woodpeckers] are considered ecosystem engineers because they make habitat for so many other species,” explained Joan.
“So, if I see some sort of hole, it is likely something lives in there?” I asked.
“It’s likely,” Joan responded.
Preferences
Eventually, the trail bent and moved away from the creek, heading out on a slowly rising wooded ridge dominated by Douglas-fir.
Standing out in the mix of trees was the statuesque Pacific madrone, with its red shredded bark and green leathery broadleaves leaning out along the trail’s edge.
“In the fall, the madrones have a lot of berries and the band-tailed pigeons were feasting,” Joan reminisced. “They were covering the trees!”
Joan also noted how madrones tend to have cavities in live trees, unlike conifers that need to be dead or dying.
I asked Joan if certain species prefer certain trees.
In general, primary cavity nesters prefer hard snags. However, there also seem to be some preferences in terms of tree species.
“Pileated Woodpeckers like grand fir,” Joan offered as an example, speculating that perhaps it had to do with the decay process. And “Red-breasted Sapsuckers like maple trees,” frequently excavating a nest in a dead branch of a live maple.
Apparently, there is an entire branch of ecology that studies the relationship between primary and secondary cavity nesters and the trees they occupy. Joan mentioned “cavity-nest webs” as a way researchers aim to delineate and describe the complexity of these relationships.
In any event, there is one consistency—“good snags are scarce” and hard to come by.
Harvest Unit
Speaking of good snags, soon Joan and I crested the hill, we broke out of the forest into a clear-cut harvest unit littered with snags and potential snags.
“It is really nice to have something out here,” said Joan referring to all the trees that were left behind.
Joan has consulted on previous harvest projects and recommended that forest managers leave more snags and live trees than might be typical in a clear-cut.
Joan pointed to a large snag with twisted branches that had been left behind.
“That snag they left isn’t worth anything because it is gnarly,” said Joan referring to the potential timber value, “but for wildlife, it is worth a lot.”
Disturbance
Joan was also quick to point out that the clear-cut itself offered some benefits to wildlife.
“There are actually a lot of species that evolved with disturbance,” Joan remarked. “Disturbance is not a bad thing.”
Species like swallows, wrens, pigeons, Purple Martin, and a whole host of raptors benefit from the opening in the canopy.
“This is a phase of forest succession—early seral,” she continued. “When it is natural it is a very diverse stage.”
Unfortunately, it wasn’t all good news in the clear-cut, as many of the shrubs that come up during the early seral stage were sprayed with herbicide to give the next generation of conifers a competitive edge.
I was also struck by the small size of the clear-cut and asked Joan about it.
“Is it good to have smaller clear-cuts?”
“There is no one good size,” said Joan.
She explained that for a forest species having a small clear-cut makes the forests more permeable—a species that wants cover can go between trees. However, the larger the clear-cut, the more valuable the area is for a species that needs open areas.
“There is always a trade-off,” said Joan. Her advice for land managers—“be as variable as possible, and work with what is there.”
Ghost Forest
As we walked past the clear-cut with the intact forest on our right, it was easy to assume that the intact forest was in some way “natural” or “right.” But, as Joan reminded me, the conifer forest only exists on this hillside as a product of colonialism.
“Before the European settlers came,” explained Joan. “Native Americans burned this area—it was a bald with scattered oak and scattered Douglas-fir. It was very open.”
With colonialism came fire suppression and the conversion of oak woodlands and prairies into forests.
“If you look in this forest now, you can find old oak trees,” said Joan. “You can tell they are open grow with lateral limbs, but they are dead and decaying…”—overshadowed by Douglas-fir.
We looked deep into the thicket of forest for one of these “ghost oaks,” and found what looked like a mossy, dead limped giant of an oak tree.
“There used to be a bird species that used those,” remarked Joan. “Lewis’s woodpecker—iridescent green with a red breast—they valued the oak and ponderosa pine.”
She sighed, “Now, they don’t nest here. There is not the habitat for them.”
Purple Martin
Then we passed it—a white sci-fi-looking apparatus on the hillside to the left.
“Here is my Purple Martin gourd rack,” laughed Joan. “It is ugly as sin!”
However, what it lacks in aesthetics, it makes up for in function.
Joan explained that the rack is put up to provide a temporary nesting opportunity for Purple Martin—a threatened species here in the west. As insectivores, Purple Martin hunt insects on the wing, so in addition to needing natural cavities for nesting, they also need open space for hunting—a difficult combination to achieve these days.
“The public land has all the big snags but is too dense, and the private land has open areas but not the snags,” explained Joan.
The rack is meant to provide temporary housing until the woodpeckers can create the cavities in snags Purple Martin needs.
However, she cautions people from putting up their own gourd racks. The eastern population of Purple Martin are entirely dependent on people for nesting for this reason. She wants to avoid this in the West.
“Purple martins are the poster child for snags,” she proclaimed.
Across the clearing, I saw a small cavity in a Pacific Madrone. I asked Joan if that might work for the Purple Martin or some other species.
“It looks good for a pygmy owl,” she replied, “but I am not sure they would want to be out in the open. A flicker would love it,” she laughed.
What about Yew?
We were nearing our turn off into the woods when we happened past a shaggy-looking Pacific Yew.
“They always make me think of old forests,” Joan smiled.
“Does it do anything for wildlife?” I asked.
“I don’t know anything in particular,” Joan replied. “They are good for cover,” she offered.
What about Joan? We knew what the Yew was up to (being a really cool tree!), but what about Yew? I questioned Joan, pun intended.
“Right now, I am working on Purple Martin stuff,” she said—tracking them with GPS in collaboration with Klamath Bird Observatory and trying to figure out where they go in winter. So far, she has found that they spend some time in Baja—sounds pretty good to me.
“That is one thing,” she said. “I am trying to finish a bunch of projects,” Joan confessed in preparation for retirement before the end of the year—that also sounds pretty good to me. Maybe she will have to visit Baja?
“Another project is not birds,” she continued, but a carnivore survey using camera traps in the Klamath Network of National Parks.
“We are looking for Marten, Fisher, and Sierra Nevada Red Fox,” said Joan.
She explained that there is a lot of interest in carnivores. They are not only sensitive to environmental change and have been facing declining population rates, but they are also an important part of the food web.
Dense Woods
We were on the steep downhill return trail when I spotted a large patch of Oregon Grape out of the corner of my eye.
“Do they help birds?” I wondered out loud.
“I don’t know,” Joan responded thoughtfully. “The hummingbirds love the flowers.”
Soon we were considering the Oregon Grape fruits and species that might benefit from them as a food source as well.
In the distance, Joan heard the call of a Kinglet deep in the woods. Kinglets, she told me, were birds that responded negatively to thinning in her graduate research.
“They are beautiful little birds,” she described. “A bright gold crest with a scarlet, orange stripe down the middle.”
She heard the call again—“high and thin.” Whatever she was hearing, I didn’t register.
Learning Birds
“Is it hard to tell birds apart?” I asked.
“Not for me,” she laughed. “But yes.”
So how does one learn? Joan had a few tips.
First, “Come during the off-season,” she suggested. Learn the birds that are common year-round and learn them one at a time.
Second, she recommended using an app, like the Merlin App to help, as it identified with sound, and you can get the results often right away.
Finally, get a feeder. Feeders are an excellent way to meet several of the birds that are around all the time.
Some starter birds include song sparrows, dark-eyed junco, chickadees, nuthatches, and towhees.
It also doesn’t hurt to have a bird with a favorite song. Sometimes that is enough to draw one in.
“My favorite is the hermit thrush,” said Joan—a high-elevation bird with a song. “It sounds flute-like and ethereal.”
I recalled hearing the bird myself while hiking in the Jefferson Wilderness—singing its heart out well into the evening. Afterward, I had to find out what I was hearing!
Help the Birds
The trail continued down through the dense forest before dropping us back on the wide gravel road we had come up on—back in the riparian forest.
As we made our way back down to our cars, I asked Joan if she had any tips for helping birds.
“The biggest problems are hitting windows, lights during migration, and cats,” she continued.
So, to help with that, she suggests putting bird strike prevention on any windows that might fool birds, turning out the lights during migration, and keeping pet cats indoors.
Now, with advancements in bird tracking, you can find out when birds migrate through your area, so you know when dark skies are most important.
Pesticides are another concern she brought up.
“Anything that affects insects affects birds.”
Brown Creeper
“Well, we didn’t see very many birds,” Joan remarked when were just about at our cars.
Then, she spotted something up in the trees—a small brown bird hopping up the trunk. It was a Brown Creeper.
“They go way up and then they fly down to the base of the tree or their nest,” Joan noted.
I watched the Brown Creeper hop its way up a large Douglas-fir trunk before taking flight and landing on another tree nearby.
It was probably feeding on spiders hidden in the bark or collecting web for its nest—a common practice according to Joan.
The light was dimming as we stood and looked up at this small brown bird doing what it does best before we lost track of it.
Trills and Thrills
“That was fun!” proclaimed Joan.
And I too felt satisfied.
We have only heard or seen a few birds, but I was walking away with more bird knowledge than I could have imagined.
High-pitched trills spilled through the trees, like a tumbling stream, as we walked the last few feet to our cars.
And I knew it was the Pacific Wren singing us off.
Joan Hagar is a Research Wildlife Biologist with the U.S. Geological Survey. She has been studying birds and other wildlife professionally for the last 30 years.
At first glance, a visit to Barnes Butte in Prineville looks a lot like much of central Oregon—a landscape of sage brush, juniper, and volcanic rimrock. It is difficult to imagine that Barnes Butte is, in fact, the inside edge of a massive supervolcano that—though now extinct—erupted more than 240 cubic miles of material forming a caldera roughly 29.5 million years ago.
Approximately 25 miles by 17 miles in size, the oblong-shaped Crooked River Caldera reaches from Smith Rock State Park in Terrebonne east to the Ochoco Reservoir and south to the Prineville Reservoir and Powell Buttes. For something so large, it might seem surprising that it wasn’t until 2005 that a couple of scientists first noticed its presence.
However, standing in the parking lot of Barnes Butte City Park with Carrie Gordon, a retired geologist, and willing hiking partner, it became obvious why such a large geological structure went unnoticed for so long. Seriously, what volcano?
The Hike
Trailhead: Barnes Butte Trailhead
Distance: Varies. (2.7 miles w/565 feet elevation to top)
Details: Large parking area; no pass required; No restrooms (port-a-potty may be available)
Introductions
It was a warm early fall day when I met Carrie in the parking lot of Barnes Butte City Park. Wildfire smoke created a haze across the skyline, but you could still just make out most of its features, including the Cascade Volcanoes in the distance.
Carrie, a small energetic woman, was all smiles as we gathered at her vehicle for introductions.
“I worked 40 years for the Forest Service,” Carrie said, “As a forest geologist.”
She explained that her job mainly entailed keeping track of material sources, like gravel.
“It is one of those careers that are just a hoot and a half,” she exclaimed.
Yes, this is Carrie. And we were just getting started.
Tall Tales
I asked Carrie to tell me about where we were standing. After all, I couldn’t see any so-called “volcano.” She quickly pulled out her geology maps from her vehicle to orient me to the space and began to weave the tale.
“Jason McClaughry and Mark Ferns from DOGAMI started mapping in 2005,” she said. Originally, “they were supposed to map a 7.5-minute quadrangle,” Carrie continued.
Plans quickly changed, however. McClaughry and Ferns were tasked with finding water resources for Prineville, but while mapping, certain geological features started reshaping their goals. By the end of the project, they had mapped over 903m2—and reshaped our understanding of central Oregon geology.
“The cool thing about geology,” Carrie began, “The rocks don’t change but the story changes. We add to our body of knowledge, and we can go, ‘oh okay’…”
Anatomy of a Calderas
Perhaps the most important change to the story that McClaughry and Ferns brought to light was the chapter on the Crooked River Caldera.
“Calderas are a little sneaky,” said Carrie.
Unlike, the very conspicuous Cascade peaks, “seeing” a caldera requires reading the landscape very differently. They are not peaks, rather, Calderas are mostly depressions.
Carrie explained: “Basic caldera formation is you have magma that is coming up to the Earth’s surface to the point you get a collapse.”
In the case of the Crooked River Caldera, these eruptions took place from about 29.7 to 27.5 million years ago. These were massive eruptions of rhyolitic lava, including volcanic tuff, that created a void below the volcano that eventually collapsed creating a 26 by 17-mile depression.
In addition, a ring fracture develops during caldera formation—allowing rhyolitic lava to intrude and bulge up along the side of the collapse.
Evidence of the ring fracture of the Crooked River Caldera can be seen at places like the Prineville Reservoir and Peter Ogden Wayside, where older rock that pre-dates the eruptions is tipping toward the interior of the caldera.
In addition, and perhaps even more obvious, rhyolitic domes can be observed marking the Crooked River Caldera Boundary. Carrie pointed to each—Powell Butte, Gray Butte, Grizzly Mountain, and, of course, Barnes Butte.
“This is the evidence that they [McClaughry and Ferns] found,” Carrie stated.
Looking out toward Gray Butte and Grizzly Peak (photo credit: Carrie Gordon)
Tuffs
I was beginning to see it—with many of the peaks visible from the parking lot—the caldera was taking form when Carrie whipped out another visual aid.
“I brought my box of rocks too,” she proclaimed.
Carrie pulled out two rocks with large flecks of material embedded within them—tuffs, I would soon find out.
“The cool thing about tuffs is they tell you about volcanic activity,” said Carrie. Tuffs are commonly associated with large violent eruptions as you see in caldera-forming.
“Tuffs are formed from bits and pieces of pumice and bits of rocks as it comes up through, in our case accreted terranes,” during an eruption, said Carrie. “It is a mishmash of stuff.”
Pulverized stuff mostly, like ash, but also some solid flecks of rock, like pale gray pumice, embedded in the matrix—that is tuff.
“It sparkles at you due to the crystal fraction in the ash,” described Carrie holding up two samples, her eyes sparkling more than the rocks.
Tuffs are also lighter than other forms of igneous rock, like other forms of rhyolite and basalt, as they are full of air pockets. She handed me one of the tuffs to weigh in my hand and basalt in the other—yep, I could feel the difference.
If you ever visited Smith Rock State Park, you have seen tuff. It is the tuffs that people mostly climb on.
“Easy to pound in your pins,” Carrie remarked.
Tuffs from the Crooked River Caldera
Geochemistry and Cooling
Carrie had other rock samples in her box. She pulled out a shiny, black rock called obsidian, and a striped rock called banded rhyolite.
“These are all rhyolite geochemistry,” said Carrie. “Rhyolite has higher silica content than basalt and it tends to be blocky when it chills.”
However, the similarities end there.
“The thing about rhyolite is it comes in so many different forms.”
Tuff is the result of violent eruptions that pulverize rock, while obsidian and banded rhyolite are both formed as lava flows.
Obsidian is glassy because it cooled quickly enough that crystals were unable to form. Banded rhyolite, on the other hand, forms crystals that capture the layering that often occurs as lava flows.
“This is what makes up Grizzly and Gray Butte…” Carrie added, holding up the banded rhyolite.
She continued, holding up the two tuffs she had pulled out originally.
Tuffs to the left and obsidian to the right
“These are the same rock,” she explained. Only one had undergone a form of hydrothermal alteration, turning it “pistachio green,” while the other more “beigy” rock had not.
“And that is tuff,” Carrie concluded, putting her rocks back in her box.
She also mentioned granite—another form of rhyolite formed by a slow cooling process under the Earth’s surface.
“It is the same composition as obsidian,” Carrie reiterated, but “buried a long time.”
Just one more reminder to not take your rhyolite for “granite” (pun intended).
More samples from Carrie’s box of rocks
Off to the Races
At this point, we had been chatting for about 20 minutes and decided it was about time to hit the trail. The trail system at Barnes Butte City Park is rather extensive, but we kept it simple and headed up the Jockey Trail that goes along the base of Barnes Butte—an old trail that the landowners used to run horses on.
As we started off on the rocky, dusty path, Carrie told me about the other trails that run through the park.
Apparently, much of the land was an old ranch. In addition to hiking the old horse track, there are also a lot of old cattle trails that are now hiking/biking trails that run through old grazing fields and around what used to be an irrigation pond.
Before that, there was even mercury mined on the Butte for a short time.
“See the main draw,” she said looking up toward the butte, “ there is an old BLM road that goes up to where the mercury mines in the 1940s are…. [The mercury mine is] courtesy of the caldera and volcanism.”
Mercury, lead, and gold, as well as Oregon’s state rock, the thunder eggs, rely on silica-rich waters to concentrate and form these minerals.
“You can take a footpath to the top of the butte,” Carrie added, “there are a lot of options.”
Rivers in the Sky
Soon we arrived at an embankment, apparently part of the old irrigation pond, when Carrie unexpectedly began hiking off the trail up the hill.
“What are you seeing?” she asked me, as I followed her onto the side of the embankment.
“Looks like some kind of layer of fine sandy stuff…” I responded hesitantly, “Oh, and the rocks are rounded.”
“You got it!” she proclaimed with a smile. “So, what we are seeing is lakebed and riverbed sands and cobble.”
Then turning, she pointed out to a suite of rimrock, lava plateaus.
“If you look across at our plateaus,” she explained, “you are looking at the old valley floors!”
She explained that each lava plateau was the result of an individual basalt eruption event (part of the Deschutes formation) that filled the valley at that point in time—the oldest being 7 million years old and the youngest only 3 million years.
Over time, the land area surrounding the lava-filled river channels eroded. As a result, what were once lowlands and river channels, are now basalt plateaus.
“This is inverted topography,” said Carrie—what was low is now high.
“What we are looking at here is the infill,” said Carrie looking back to the sand and cobbles, “the eroded remains of a valley bottom.”
Looking out at the lava plateaus
Perspectives
Carrie and I continue wrapping up and around the hill of infill where we could get a better view of the young lava flows and the much older rhyolite buttes of the Crooked River Caldera.
As we hiked, we passed by some bright yellow rabbitbrush still in bloom. Carrie told me how she uses it to make cloth dye; and we briefly got on a tangent regarding natural dyes—a side passion of Carrie’s.
“Rabbitbrush makes the best dye!” she proclaimed.
Speaking of color, Carrie pointed out a pale green patch of ground in the distance—to the left of Barnes Butte from where we stood.
She told me how she used to drive by and wondered at the green color—“it just stayed pistachio green” all year long. Eventually, she realized it was tuff.
Though the rock that makes up Barnes butte is a solid rhyolite dome, tuffs can be observed around Barnes Butte as a few outcroppings, and as what geologists call “float”—rocks that have moved from their place of origin.
Carrie pointed out a few outcroppings of Barnes Butte tuff that lay just in front of us—“the high points,” she noted.
A Step Back
Carrie also addressed the hills that lay on the far horizon, outside the Caldera’s boundary.
“Most of what we are looking at on the far horizon are Clarno andesites,” said Carrie looking east—volcanic rocks from a period preceding the Crooked River Caldera eruptions.
Of course, mixed up in all of it, is even older rocks. Accreted terranes—jumbles of earth materials that become permanently attached to a land mass of a completely different origin—make up the basement rocks of Oregon.
Carrie told me about how older maps used to show a pocket of limestone in the area. It was “weird” at first, but as Oregon’s geological story unfolded it became apparent that the limestone was from an accreted terrane. The limestone would have come from some distant shallow sea before it was added to the continent 100 to 400 million years ago by the forces of plate tectonics.
Only later it became part of the Crooked River Caldera. The past, literally, resurfacing by way of the Caldera’s eruption.
Flash Forward to Newberry
Carrie turned to face the interior of the Caldera again. There was still one more point in time to discuss.
In addition to the lava flows that make up many of the plateaus around Prineville, an even younger period of volcanic eruptions graced the Caldera in geologically recent times—the Newberry Volcanics.
Newberry has been erupting for the last 400,000 years and remains active today. Its most recent eruption was 1,300 years ago.
“Darn it all!” she exclaimed. “I was hoping it would be clearer…It [Newberry] is a big shield volcano,” said Carrie, “It barely shows over the horizon.”
Interestingly, some of Newberry’s flows reached into the Crooked River Caldera.
Carrie described one of these flows:
“That basalt flow was going down the ancestral Deschutes River, near O’Neil Junction, where it dropped into the Crooked River drainage, headed to Smith Rock. Here it smacked into Smith Rock pushing the Crooked River over to its present course.”
Those who have visited Smith Rock State Park and hiked any of its trails know this basalt flow as the calf-burning, heart-pumping climb out of the Crooked River Canyon, and back to the parking lot.
Next time you visit, “Look at what is at the bottom of the basalt flow…” advised Carrie. “There is river cobble there.”
Whether it is the Newberry basalt flow, or any one of the other flows that passed through, each time the Crooked River is displaced.
“It was doing its level best to be a valley bottom and these stupid basalt flows come in,” Carrie described in her own colorful way. “The river is like ‘okay, I will find another route’.”
Ashes to Ashes
At this point, Carrie and I resumed our walk along the old racetrack and took a left, wrapping around to the other side of the embankment facing Barnes Butte. Song birds flitted by as we walked.
“One of the best-kept secrets,” Carrie shared, “we have a nesting osprey pair here.”
As we meandered around the bend, Carrie pointed out what looked like really fine sand.
“This is volcanic ash,” she explained. “When Mazama erupted, we got a foot and a half of fine ash.”
Mount Mazama—a massive stratovolcano blew it’s top 7,700 years ago, forming a smaller caldera that has since filled with water forming Crater Lake.
Carrie continued: “One of the things that happened is the winds will blow ash and it will catch on the leeward side of the hill,” she explained.
Carrie then proceeded to scoop up a handful of the ash and show how me how to look at it with a hand lens—white pumice fragments and black hornblende or magnetite could be made out among the grains. Of course, her favorite part, and mine too, was to look at the ash in the sunlight.
“The best thing about volcanic ash is it winks at you,” said Carrie. “It is the reflection of the crystal fragment of volcanic ash.”
You don’t get that same winking with sand, explained Carrie. Only ash has the ability to sparkle.
Volcanic ash capable of winking in the sun
Blowing in the Wind
The ash is also important to the soil of the area. Loess—windblown sediment—is rich in many minerals and provides the starting material from which soil forms.
Of course, loess is not the only input into the area.
“Don’t forget we are in this pocket here,” reminded Carrie, “We had all the river systems and lake deposits that are actual sand and gravel.”
Alluvium—water-transported sediment—also contributes to soil formation, even in places you might not expect. Powell Butte, for example, is mostly covered with river sand.
“Something [i.e., a river] was moving across there at one time,” said Carrie.
Now, these old river channels are a ready source of water for the City of Prineville. When the City looked for places to tap for wells, surprisingly the best places were on the bottoms of the lava flows that once were river channels.
“This was the thing that blew me away,” Carrie smiled.
Barnes Butte
Carrie and I reached another junction and took the trail heading up Barnes Butte. As we climbed, we passed by several large hunks of reddish-brown rock. Unlike the rocks down below, these were not round, but jagged.
“All the hunks of rock are rhyolite,” said Carrie.
I asked Carrie how she knew it was rhyolite, aside from knowing where we are at. Carrie picked up a piece of the rock and knocked it against another.
“It sounds glassy,” she explained. “Part is how it sounds, and if you can heft it.”
According to Carrie, compared to basalt, another prolific volcanic rock, rhyolite is not as heavy. So if you find a gray rock that is relatively lighter and glassier, it could be rhyolite.
Juniper
As we continued up the rocky hill Carrie, I noticed a juniper with its roots clinging to a juniper tree.
Off-hand I asked Carrie, “Do junipers like rhyolite?”
Surprisingly, she answered in the affirmative.
“That’s a cool story!” Carrie proclaimed. “Western Juniper has become invasive.”
Though western juniper is a species native to central Oregon, it has been creeping into areas that it normally wouldn’t. Fire exclusion, grazing pressure, and climate variability have all been cited as reasons for the spread of the waster juniper.
“And it uses a lot of water,” Carrie added, a highly valued resource in the area.
“This is all rangeland,” Carrie explained, it should have “more grasses and sagebrush component.”
In short, western juniper shouldn’t be so prevalent.
Instead, according to Carrie, western juniper is a first colonizer. Its range historically was limited to rocky areas—like our rock-grasping juniper.
“This is a rhyolite knob,” concluded Carrie, “and this is a very well-behaved juniper.”
Well-behaved journal growing from rhyolite rocks
Lichen
We continued up the Barnes Butte for a stretch but then decided to turn around. I was curious about finding tuff, so Carrie suggested we check the lower trail.
As we walked, I started noticing all the lichen and moss growing on the rhyolite and asked Carrie about it.
“Are they picky?” I asked, wondering if only certain lichen grow on certain kinds of rock.
Carrie didn’t think so, but instead mentioned how they might be used to age-date rocks.
Estimates of the age of a rock can be estimated based on the growth and size of the lichen that grows on it.
“Has the rock been sitting in place?” Carrie asked rhetorically. “Then you can get some age dates.”
Additionally, some plants do seem to prefer certain rock types. During the mapping of Mill Creek—an area adjacent to the Crooked River Caldera—McClaughry and Ferns found that, following a fire, much of the rhyolitic rocks were being colonized with manzanita. Manzanita soon became an indicator of rhyolite geology during the mapping.
Lichen growing on rhyolite
Recommendations
As we continued downhill, Carrie spotted some of the green tuff as float (loose rock) along the pathway—more evidence that we were, in fact, in a Caldera.
As we walked, Carrie offered me a lot of recommendations—video recommendations, places to visit, and hikes to take. She had a real knack for suggesting hikes I hadn’t been on.
But perhaps the strongest suggestion she has was to check out some of the Crooked River Caldera sites.
One of these places was Pilot Butte. (Yep, I hadn’t hiked it yet.)
You can see the Cascade Volcanoes from Pilot Butte—” a lovely white line of volcanoes,” as Carrie put it, but she wanted to make sure I didn’t miss the main event.
“It [the Crooked River Caldera] is one huge volcano compared to the pretty pristine cones,” she added.
Other places she recommended for observing attributes of the Caldera include the Prineville Reservoir, Peter Skene Ogden State Park, Ochoco Reservoir, and, of course, Smith Rock.
I recommend hiking with Carrie. She is a hoot-and-a-half.
Carrie Gordon is a retired forest geologist. She was the Forest Geologist on the Ochoco National Forest and Crooked River National Grassland, U.S. Forest Service, headquartered in Prineville, OR. She retired in 2017. Carrie is also an active member of the Central Oregon Geoscience Society and an Oregon Master Naturalist through the OSU extension program. Carrie has had a life-long fascination with the land and the rocks, listening to the stories they tell.
A few times a year the tides swell to levels much higher than are typical. These royally high tides are known as King Tides and occur over a few days period, typically in the months of November, December, and January.
With the King Tides, comes a whole host of changes to the coastline—local flooding, potentially increased erosion, and an overall increase in coastal hazard risk. However, King Tides are not necessarily something to run from. Many people flock to the coast to see the King Tides—the crashing waves and high surf are a definitive draw for many wave watchers.
King Tides also offers an opportunity to participate in some community science. Oregon King Tides Project, by the Oregon Coastal Management Program and CoastWatch, ask local Oregonians to snap some pictures of these extremely high tides and post them to their site. The goal of the project is to help coastal communities see their vulnerabilities, especially considering future climate change, so they can better adapt and prepare.
I wanted to learn more about sea level rise on Oregon’s Coast and experience the King Tides. So, I reached out to Alessandra Burgos of Cascadia CoPes Hub to see if she was open to a coastal ramble. She agreed.
It was time to head to the beach.
The Hike
Trailhead: No Official Trailhead (Start on Avenue U and end at 12th Avenue)
Distance: 1.5 miles one way on the pavement; the trail is level.
Details: Park on the street or Public Parking at the North End of the Promenade. Public restrooms at North End. The promenade is open to hiking/running and biking. It is a popular spot and can be very busy.
Here Comes the King
It was a mostly sunny winter day during king tides week when Ali (Alessandra) and I met for a walk along the Seaside waterfront. If you want to talk about the ocean, it helps to have a clear view of it as you go.
Immediately, Ali’s dark brown eyes scanned the surf. The waves were coming in fast and there wasn’t much beach left uncovered. The tide was in, way in.
“I have never been here before,” Ali confessed, “but I would imagine the beach is usually much bigger.”
I tried to imagine what it might look like on a “normal” day. Even having been there, I couldn’t picture it.
“It would be nice to have a before and after,” I confessed.
Before and after picture aside, what we were seeing were king tides—unusually high-water levels at high tide that were expected to continue for the next few days. Begging the question—why?
Ebb and Flow
“What happens with tides is you have the gravitational pull of the moon, which is the strongest force,” Ali explained.
You may have heard that the moon creates tides—and this is mostly true. As the Earth rotates and the moon revolves around the Earth, its gravitational pull causes the ocean to bulge in the direction the moon is facing. This bulge is dragged around the Earth, like a magnet, as it rotates. There is also a bulge opposite the moon due to a lack of gravitational pull by the moon at this alignment.
However, that is not the entire story. As Ali explained: “Then you also have the gravitational pull of the sun, and even though the sun is bigger, it is further away so you don’t get as big a pull.”
However, when the sun, moon, and Earth are in alignment—you get a very high, high tide and a very low, low tide.
“For king tides, everything is in a perfect wonderful alignment,” Ali explained. “The moon is either a full moon or new moon… “ and is in line with the Earth and Sun. This causes a higher gravitational pull on the oceans causing these king tides.
At the time of our hike, it was a new moon. In a couple of days, the king tides would be at their peak.
“You can see over there it is higher than normal and those wonderful waves rolling in,” Ali pointed out toward the ocean waves again. They were really moving.
The water level at near high tide with waves rolling in.
1 Tide, 2 Tides, 4 Tides, More
“Why do we get two tides here?” I asked next as we sauntered our way down a path to the packed sandy beach.
“That [slightly] has to do with where you are in latitude [because of how the continents are spread out],” Ali responded. “And [mostly] it has to do with the shape of the ocean basin.”
She also reminded me that we have two bulges making their way around the Earth in a 24-hour period, so there are both two high tides, and two corresponding low tides.
If there were no continents there would be 2 equally proportioned high and low tides every lunar day. The land masses block the movement of the tidal bulge resulting in different tidal patterns. On the West coast, we experience mixed semidiurnal tides meaning “You have a high, high tide, low, high tide, low, low tide, and high, low tide… four tides,” Ali listed the different tides, but it came out more like a tongue twister.
We were walking the beach during our high, high tide.
Most places on the Earth experience two tidal cycles. However, there are some places that have only one high tide due to the shape of the ocean basin. The Gulf of Mexico, for example, has diurnal tides, experiencing one high tide and low tide on a lunar day.
A Rough Start
Ali and I headed north along the sandy beach—the waves rolled in a short distance away from us. I asked Ali to share a little about herself and how she ended up in her current position.
“I grew up on the East Coast in Philadelphia. Went to school at Rutgers in New Jersey where I was a meteorology major,” Ali began.
She always had an interest in the weather and was planning to be a broadcast meteorologist when she finished college. But her plans changed when Hurricane Sandy hit New Jersey during her Freshman year of college.
“You saw the destruction… you saw all the trees down, during the night transformers blowing up, huge lines at the gas station… so that really formed what I wanted to do with my life.”
After that Ali became more interested in flooding and the Oceans. She went on to study oceanography at Old Dominion University in Norfolk, VA where she earned a Master of Science.
“Norfolk, VA is home to the largest Navy base in the world,” Ali explained. “So, as you can imagine, they were very interested in mitigating against sea level rise.”
Rising to New Challenges
After that, Ali moved to Washington D.C. as a Sea Grant Knauss fellow and was introduced to policy and worked on coastal resiliency issues.
“Then the pandemic hit, and I lost my job at the time,” Ali went on. “My friend was moving to Portland, and I always wanted to visit the west coast, so I packed up and came here.”
Finally, after a short stint at UC Santa Barbara, Ali was hired by Oregon State University in her current position—program manager for the Cascadia Coastline Peoples Hazard Research Hub, or Cascadia CoPes Hub.
“I have been there a year,” said Ali. “It has been a whirlwind of information… There are over 90 people associated with the project now.”
That is a lot to manage.
Ali Burgos posing for a picture on the promenade.
Collaboration
We hiked on, the sun warming us and the sand firm under our feet. Ali told me more about Cascadia CoPes Hub in fits and starts as we walked along taking in the scenery.
“In a nutshell, It’s a 5-year funded project from the National Science Foundation. We are trying to help coastal communities in the Pacific Northwest increase their coastal resiliency,” explained Ali.
Cascadia CoPes Hub is a newer collaborative (it started only about 6 months before Ali was hired) with multiple teams working on different aspects of coastal hazards research and outreach. Ali outlined the focus of each team.
Team 1 is geohazards. This team deals with research around earthquakes, tsunamis, and landslides.
Team 2 is coastal inundation. This team is looking at sea level rise, erosion, flooding, and overall storminess.
Team 3 is community adaptation. Team 3 wants to know what coastal communities are thinking—what do people value? What do they perceive as threats? And how do they get that information?
“This is where the social scientists live,” said Ali.
Team 4 is the STEAM team. STEAM stands for science, technology, engineering, art, and math. And the goal of this team is to bring underrepresented students into STEAM through a fellowship program.
And finally, Team 5 is community engagement and co-production.
“Coproduction is kind of a buzzword in research right now,” Ali explained. “Coproduction is working outside your discipline or field to create new ideas, solutions, and knowledge.” It often involves working with communities, state agencies, as well as other academics.
“We keep growing… There were 60 people when I started, and now there are 90 plus.”
Fading from Gray to Green
As we hiked on the broad plain of sand, Ali pointed out just how low-lying the beach was.
“If you look at the beach here,” she remarked pointing about, “we are as flat as flat can be.” Not a good place to be if the water came up too high in a storm—not a lot of protection.
However, looking over toward the City of Seaside, a low wall wrapped along the promenade in front of all the buildings—wouldn’t that offer some protection?
“Over there we have some seawall,” Ali said, pointing to the structure.
Ali referred to the wall as a form of grey infrastructure—a manmade structure built for, in this case, protection from flooding and storms.
“I am not a fan, personally,” she went on. “It has its merits in certain situations, but seawalls can cause more erosion of the beach… And how tall do you make it?”
Seaside waterfront properties with seawall in front.
As if on cue, the open sand we were walking shifted—wide mounds of grassy sand dunes rose up in front of us.
“These are green infrastructure,” Ali explained. “This will help block wave energy during storms.”
Unlike seawalls, dunes collect sand, rather than letting it erode. As natural-based features, dunes can grow and change over time. “Plus, it can help with habitat,” Ali added.
“Natural and nature-based features are what people are going more towards,” said Ali.
Ali also mentioned cobble revetments as another example of grey-green infrastructure. Essentially, a berm made of pebbles or cobbles mimics natural rocky beaches—water can move through the rocks, while sand can still build up.
“This is a great dune system,” Ali smiled as we headed through the dunes on what little beach was left.
Low dunes along the northern stretch of the promenade.
On Shaky Ground
Soon the beach was all but gone and Ali and I decided to move to the pavement. We took some stone steps up and onto the Seaside promenade and continued our walk north.
As we walked, I asked Ali how she felt about the earthquake and tsunami hazards in the Pacific Northwest.
“It is definitely something I grapple with moving here,” Ali responded.
For those that haven’t heard, the Pacific Northwest is predicted to experience a high magnitude (possibly 9+) megathrust earthquake in the next 50 years. Current predictions estimate a 37% chance of a 7.1+ in the next 50 years according to oregon.gov. This will also result in huge tsunamis up and down the coast.
“What is most interesting about that is human perspectives—trying to understand how people see their vulnerability,” Ali continued. “It is easy to go day by day, especially if you don’t have past experience, to become very complacent.”
Sign at the end of the promenade marking the tsunami evacuation route.
Keeping Perspective
I asked Ali what she thought people should be doing considering the megathrust and tsunami risk in Oregon.
She suggested keeping things in perspective. Yes, there is a risk associated with visiting and living on the coast, but it is still very small.
“Even on my drive down this morning, I get anxiety about coming over here,” she confessed.
However, she also knows that the odds are in her favor.
“I am more likely to get injured in my drive,” she added.
So, what should people visiting or living on the coast focus on? Being prepared. That is what her research cooperative is trying to do—help people know how best to do this on a place-by-place basis.
“What is the most important thing to know to prepare?” I asked.
“I think the biggest thing is to know your evacuation route,” Ali suggested. “Many people don’t know which way to go, especially if you’re visiting.”
Whenever the Cascadia megathrust earthquake hits, there will be little time to move to high ground—perhaps as little as 10-20 minutes at best. So, look at the evacuation maps ahead of time and have a plan A and a plan B.
On cue, Ali and I reached the end of the promenade trail, where a tsunami evacuation map was prominently posted.
“Moving here, I learned a lot more about earthquakes and tsunamis than maybe I want to know,” Ali laughed nervously.
I hear that, Ali.
Map of the tsunami evacuation route was posted at the end of the promenade.
Winter is Coming
Upon reaching the end of the trail, Ali and I about-faced for a return journey. This time we stuck to the paved walk that took us past the waterfront buildings—just a seawall in some spots for protection. Our conversation pivoted back to issues with high water. Ali was going to be speaking for the King Tides Community Science Initiative the following day about sea level rise, and with King Tides rolling in, it seemed important that we return to coastal inundation. Plus, I had a lot of questions.
On the top of my mind was winter—why were king tides so notable in the winter? I asked Ali.
“They are worse in the winter,” she responded, “because of the Earth’s orbit around the sun. We are closer to the sun in the winter so the gravitational pull is stronger… winter king tides are going to be stronger.”
One of the biggest Earth Science misconceptions is that the Earth is farther from the sun in the Northern Hemisphere winter, resulting in a change in seasons, but the opposite is true. Fun fact, seasonal shifts have more to do with the tilt of the Earth in relation to the sun. (You have just been scienced!)
Additives
Then of course there are the potential additive effects of storms which are more common on the Oregon coast in winter. I asked Ali to explain how storm surge and waves play a role in water levels.
“Storm surge is basically when you have a storm coming up the coast. You have low atmospheric pressure… with a lot more wind. The winds and pressure are forcing the water up—that is basically your storm surge. This can be coupled with high tides, which could make flooding worse.”
Ali explained how the wind is a result of pressure differences along the Earth, which are greater in the winter. And high winds equal bigger waves, which have harmful effects.
“Winter storms come through and produce a lot more wave energy,” Ali explained. “Those big waves can move sand around, cause erosion, and bring in a lot of debris.”
Both storm surges and big waves happen all the time, but with high tides, the consequences are magnified.
Rise Up
So, what about sea level rise, overall? What can we expect there?
There are two major contributors to sea level rise, according to Ali: 1) melting glaciers from Greenland and Antarctica, and 2) warming oceans.
How melting glaciers contribute to sea level rise is straightforward: glaciers add water from the land into the ocean, literally filling up the global bathtub, as it were.
Warming oceans affect sea level in a different way—causing the same amount of water to take up more space. As the water warms, the water molecules move apart in their higher energy state, taking up more space—something called thermal expansion.
Variability
Of course, there is some variability.
“Thermal expansion and ice melt aren’t uniform,” explained Ali.
Plus, there are other factors having an effect including changes in currents due to climate change and differences in vertical land movement.
There are sea level rise hot spots, as well as places that aren’t seeing any sea level rise at all.
Luckily, sea level rise has been slower along the Oregon coast overall—mostly because the land is rising too, counteracting sea level rise in some locations.
“Global mean sea level rise is 3.4 mm,” said Ali. “Oregon is not anywhere near that.”
Another El Niño
Then there is natural variability related to whether we are in a La Niña or El Niño year.
“ We have been in a La Niña for the past three years,” explained Ali.
La Niña brings colder weather and more precipitation to the Pacific Northwest.
“Which is great for skiing,” she chimed.
In an El Niño year, the oceans will warm—which could lead to greater thermal expansion and other issues associated with a warmer climate.
“And with climate change,” Ali added, “they may become more frequent and more severe.
“The biggest thing with sea level rise is your basic water gets higher—everything is happening on a higher base,” Ali explained.
In other words, a higher sea level means a higher storm surge and high wave energy eroding places it never reached before. King tides would be higher than they are now, and the next El Niño year, more severe.
Act Now
“What should we do?” I asked Ali.
“Our oceans are rising, that is fact,” Ali responded. “How much and when, is the biggest thing to think about, and what do emergency managers need to think about.”
More specifically, Ali recommended creating more natural and nature-based features on the coast as the first line of defense against inundation.
Another option—is managed retreat. Managed retreat is a planned process of moving buildings and people further inland to avoid hazards and risks.
“Managed retreat isn’t popular, but something to think about,” said Ali.
Ali was quick to add that, managed retreat isn’t something that she is in a rush to see happen in Oregon. Oregon isn’t facing a sea level rise crisis currently, so it probably isn’t as important a strategy right now. However, in the broad scheme of things, Ali was clear that managed retreat is important to adapt to sea level rise.
Predicting the Future
We were nearing our starting point on the promenade when we passed by a decorated tree or bush opposite the seawall. I snapped a picture. It seemed important for some reason. An emblem of the community perhaps?
Considering the community, what is the future of sea level rise?
“Sea level rise is exponential right now,” Ali told me as we walked. “Not on a linear increase. The rate is getting faster.”
“Why is that?” I asked.
“Warming and melt is on a lag, “ Ali explained. “Even if we stopped emissions right now, the oceans will continue to rise.”
And continue to rise, in theory, indefinitely.
“It is hard sometimes,” Ali paused. “People say ‘you are just doom and gloom’… There is a fine balance to walk—understanding the risks but knowing there is something we can do.”
Holiday “tree” along the promenade.
Incoming Storm
Ali and I were still discussing sea level rise when we got to the point where we could see the waves and an access point to the beach.
“The water is straight up to the edge,” Ali proclaimed referring to our coastal view. “High tide today is about 8-9 feet. It is normally 2-4 feet.”
We headed down to check out the waves from a better vantage point.
As we walked out toward the pounding waves, Ali told me more about ocean waves and how they are generated.
“The wave energy is coming from the wind,” she began. The longer the fetch (the length of water that the wind can blow without being blocked) the more energy can be imparted into the ocean allowing waves to grow larger.
She went on to explain how the low-pressure system that generates the storm also has a small effect by pushing water up due to the inverted barometer effect.
“If you have low pressure the water is going up. High pressure it gets pushed down,” Ali described.
All that said, it was clear to Ali that a storm system was on its way. Waves were rushing up fast, breaking quickly, and curving ferociously—all signs of an incoming storm.
“They [the waves] are definitely stronger,” she remarked as we stopped and stared. “And it’s happening pretty far offshore… and getting those nice curves to them.”
I looked out toward the ocean to try and see what Ali was seeing. I hadn’t considered this idea before—that I could look at the ocean and predict the future.
Staring out at the rhythmic movement of the incoming waves—it all started falling into place.
Reflections
Our oceans are sending us warning signals. They warn us of storm systems coming through hours to days in advance. But more than that, they warn us of impending changes to our planet that we can’t afford to ignore.
Visiting the coast during king tides can be a lot of fun—people flock to the coast to see the massive waves and enjoy the pounding surf—but they are also a reminder that our planet is changing.
Our oceans are warming quickly, and the global sea level is rising, resulting in a multitude of changes to Earth and human systems.
The signs are there. We just need to learn how to see them.
Alessandra (Ali) Burgos a project manager for Cascadia Coastlines and Peoples Hazards Research Hub with Oregon State University. Ali earned a Bachelor of Science in Meteorology at Rutgers University and a Master of Science in oceanography at Old Dominion University.
The land and ocean may seem like separate entities—one solid and secure and the other a watery depth—but the connection between the two is multifold and profound.
Salmonids provide one such connection. Salmon are considered anadromous, meaning they travel between their freshwater birthplace, to the ocean, and back. Upon returning home, they spawn the next generation of salmon before they inevitably die—completing their lifecycle.
By feeding in the ocean for anywhere from two to seven years, depending on the species, salmon bring marine nutrients to the terrestrial environment. Streamside vegetation gets anywhere from just under 25% to 70% of its nitrogen from salmon. Studies have shown in at least some instances, trees grow faster near salmon nesting grounds.
Salmon are also culturally important fish—providing food for people of the Pacific Northwest for thousands of years. And, in modern times, salmon fisheries have grown in scale and significance. As a result, salmon have also received a lot of attention from the scientific world.
Yet, despite the vast amount of research done on salmon, there is still a lot that is unknown about salmonid species, especially when it comes to their time spent in the ocean.
This is where Laurie Weitkamp comes in. A marine ecologist with NOAA, Laurie has been studying salmon her entire career—working to understand their complex behaviors and lifestyles to better inform fisheries management. In recent years, she has joined multi-week expeditions in the Pacific Ocean in pursuit of a better understanding of their marine life.
I met with Laurie at a local trail in Newport with the hopes of gaining keener insight into her research. We also planned to hunt for chanterelle mushrooms along the way.
Fish and fungi—now there is nothing more Pacific Northwest than that!
Conserving Fish
Laurie and I began our hike on a gravel road shaded by Sitka spruce and western hemlock—a quintessential coastal forest. It had rained a lot the night before, but this morning was mild and comfortable as we followed the road downhill.
As we walked, I asked Laurie for a quick bio.
“I have been a research fisheries biologist for the Northwest Fisheries Science Center—one of, I think, six regional Centers around the country, and part of NOAA fisheries,” Laurie described. “I have been doing this for 30 years now.”
“Congratulations,” I exclaimed. “That is an accomplishment.”
So, what has Laurie been up to these last 30 years?
It turns out, quite a lot!
Laurie is a salmon biologist with a strong focus on salmon conservation. One of her main projects over the years has been to provide 5-year status updates on West Coast Coho—a threatened salmon species under the Endangered Species Act. In fact, she was the lead author of the West Coast Coho Status Review which led to its original listing back in 1994-95.
“We just finished our status review update with data from 2019,” said Laurie.
You couldn’t tell just by looking at her, but Laurie is a rockstar salmon biologist.
Hatchery Fish Problem
As Laurie and I continued following the gravel path, we got to talking about the hatchery fish problem.
Hatchery fish are ubiquitous. Bred to improve salmon populations, but they have taken a toll on wild population fitness.
In fact, according to Laurie, stray hatchery fish was a major factor in the original ESA listing for Coho.
“Hatchery fish are essential to fisheries,” Laurie explained, but when we don’t keep tabs on them, that creates a problem. “You can’t tell what is going on [to wild populations],” in that case.
“There is a lot of evidence that when you get all of these hatchery fish it depressed the fitness of wild populations,” Laurie went on.
There are studies that have shown this. Breed a wild fish with a hatchery fish and they have fewer offspring. Though it is unclear why.
For these reasons, Laurie has differentiated between hatchery fish and wild fish populations in her conservation and policy work.
Wild populations “are the building blocks,” she explained. “They are critical to the continuation of the species,” deemed “evolutionarily significant.”
Stay Wild
Therefore, to keep wild populations wild, a few things needed to change.
Fortunately, a lot has changed since the original ESA listings.
“One of the things the state of Oregon did is close down all the Oregon Coast hatcheries. We went from eight million to 300,000 hatchery fish, so they effectively shut down.”
The other thing that changed is Oregon started marking hatchery fish by removing their adipose fin before releasing them.
“It is all automated,” said Laurie. “They go into a slot, measure how long the fish is… and clip…thousands are done per hour.”
The results of these changes have been positive.
For one, the “wild population increased in productivity by 25%,” said Laurie.
Second, these “evolutionarily significant” wild fish are protected from fishermen. “
You aren’t allowed to keep anything that has an adipose fin,” Laurie explained. “That is huge! And in response to ESA listing.”
Change is a Coming
The ESA listing of salmon species has resulted in other changes as well.
For example, land policy has changed. Laurie mentioned the Oregon Forest Practices Act update—requiring larger buffer zones on streams to protect fish.
Despite these changes, salmon populations are still struggling. Marine heatwaves have knocked down populations. And no ESA-listed salmon population has been delisted.
For some, this may be seen as a failure, but not for Laurie.
“It is impressive,” she stated. “None have been taken off, but none have gone extinct.”
And there have been some wins too. Laurie told me that about 1 million sockeye returned to the Columbia this year to spawn. Perhaps the largest sockeye run since the Columbia River dams went in back in the 1930s.
Not bad, considering what salmon are up against.
Segue into Research
As we continued past more second-growth Sitka spruce on moss and fern-covered slopes, we saw someone coming from the opposite direction with a basket of chanterelles—the popular mushroom that we planned to hunt for that day.
Laurie playfully asked if had left some behind. He offered a quick “no” and a chuckle. Laurie laughed too, undeterred. Her positivity was infectious.
Then Laurie gracefully segued into her research work.
“I am trying to understand what goes on in the Ocean,” Laurie explained.
You may recall, salmon are anadromous fish. They are born in freshwater, but then spend a lot of their lives in the Ocean—some salmon species up to 7 or 8 years—before returning to their natal stream to spawn.
“A vast majority of the little guys don’t make it back,” said Laurie. “Some 95-99% of salmon that enter the Ocean do not survive…. That is kinda the odds.”
Laurie was quick to clarify that these odds are not unusual or necessarily related to human impacts. It is their survival strategy.
“The average female lays 3000 eggs,” said Laurie, “two need to survive.”
So, the question is Why? Why do so few salmon make it back?
This is the question Laurie has been aiming to answer.
Bottom-up
According to Laurie, there are two main approaches to consider when it comes to salmon loss—either top-down or bottom-up. The bottom-up approach considers how populations are controlled by the organisms at the trophic level below them, i.e., their food.
In the case of salmon, it requires looking at prey availability for the species. Depending on the species, this might be krill, jellyfish, or smaller forage fish.
So, what does Laurie’s research suggest regarding this bottom-up approach?
“If the water is cold and there is a lot of prey available,” said Laurie, “[salmon] do well.”
In other words, both cold temperatures, which help with upwelling and make the Ocean more productive, and food availability work together to regulate salmon.
According to Laurie, there is a lot of evidence that points to bottom-up being “really important.”
It is also relatively easy to study—just catch a few salmon and look in their stomachs—but it is only half the equation.
Top-down
A top-down approach suggests the opposite—that populations are controlled by organisms at the trophic level above them, i.e. their predators.
Salmon predators are numerous and become even more numerous as the oceans warm.
“When the water is really warm,” explained Laurie, “you get warm water predators that come up [from the south],” like hake or pacific whiting.
“Hake are incredibly abundant fish,” said Laurie.
Normally summer guests, with ocean warming, hake are extending their stay in the Pacific Northwest for a longer amount of time.
I Hake you
At this point, you may be thinking:
So, just how much salmon are hake consuming?
Turns out the answer is complicated.
Laurie told me about a study she was involved in that looked at how much mackerels and hake predated on salmon as they came out of the Columbia. They sampled thousands of these predators’ stomachs for about ten years and found less than a dozen salmon in their stomach contents.
“Salmon are pretty rare,” Laurie explained. “There are a hundred times more other anchovies out there that they [mackerels and hake] are feeding on.”
To add to the difficulty, the stomach contents of any fish only reflect the last 24 hours of feeding. Eat a salmon on Tuesday, by same time Wednesday, any sign that the feeding took place is gone.
Take Terns
Seabirds, like terns and cormorants, are another predator of salmon that scientists are watching.
In this case, some researchers are using tagged salmon to monitor their predation.
“They [the researchers] put pit tags in individual fish,” Laurie explained. As the birds eat the fish, they also consume their pit tags.
“Then they go over the tern and cormorant colonies after they left in winter or fall… They run over the thing and detect the salmon that were eaten and pooped out in the bird colonies.”
Counting pit tags, “those are the easy situations,” Laurie admitted.
In short, “Predation is really hard to study.”
Chanterelles
We had been hiking for about 45 minutes when we passed one of Laurie’s chanterelle spots. The ground was covered in moss and growing thick with salal and evergreen huckleberry. Tall Sitka spruce trees with their cylindrical trunks made up the overstory.
“It has not been a very good chanterelle year,” Laurie remarked as she searched the edge of the woods.
However, soon enough Laurie found one of the golden beauties.
“Chanterelles look like that,” Laurie held up her find, “with an irregular shape… and they have branched gills that are primitive gills.”
In contrast, false chanterelles have an uneven coloring compared to chanterelles—“dark in the middle and light on edges.” False chanterelles also have true gills that fork near the cap margins.
There were a lot of false chanterelles.
Nutrient Connection
As we searched the area for more chanterelles, I asked Laurie if there was any connection between salmon and chanterelles.
Her answer was a brisk “no,” but just as quickly, she reconsidered. Laurie had a quick wit about her.
“Well habitats that are good for chanterelles are also good for salmon,” she noted.
It turns out I was in the right habitat at that moment—soon I had a couple of good-sized chanterelles in my possession.
“Found two!”
Speaking of seconds, I suggested to Laurie another connection between salmon and chanterelles—nutrients.
Salmonids have a unique role in nutrient cycling—they carry marine nutrients from the ocean to inland areas. From here, fungi help decompose the dead salmon bodies, or the waste generated from an organism that consumed their bodies, releasing those marine nutrients to fertilize the coastal forest.
“There is all kinds of work that shows that trees grow faster along salmon runs,” Laurie observed.
She also mentioned the role lamprey, another anadromous species, plays in fertilizing the forest.
“It is really cool because they bring up nutrients as well,” said Laurie. “They can go up vertical surfaces…” she explained, “and they can get into places salmon cannot, and fertilize streams that salmon cannot.”
At this point we had exhausted our chanterelle patch, so we headed back to the road.
Not long after, we passed by a disturbed area where I noticed a stand of skinny alder trees. Dark green alder leaves lay scattered on the ground—another good fertilizer. Fish fungi, and trees—all helping keep the forest green.
Hiking next to a grove of alder with salmonberry understory on the left
High Seas
We were about halfway through our hike when we turned onto another road. The plan was to travel it for a while before taking a bike path back to complete a loop. This was our migratory route. But what of our fish?
As mentioned earlier, salmon move from freshwater to the ocean and back again—sometimes spending years fattening up in a marine environment. But, last I checked, the ocean is huge.
Which begs the question—where do salmon go once, they reach the deep blue?
“They head north,” Laurie asserted. Or at least most do.
Sockeye, chum, and coho all head up to Cape Flattery then onto Canada and Alaska, according to Laurie. They follow the continental shelf for a season, their paths tracked as they pass various outposts along the way, before dropping off the shelf and entering the “deep sea.”
Though, they may as well be dropping off the face of the Earth because, at that point, they could be anywhere.
“We don’t see them again until they come home,” explained Laurie. “It is like a huge washing machine out there.”
It is Laurie’s work to visit the washing machine, but more on that later.
Keeping Track
As we crunched along the gravel road, I asked Laurie to tell me more about how scientists were tracking fish.
Even before salmon enter the deep sea, they are difficult to track. As Laurie put it—“we get mixed results.”
“The number of fish you need to tag to get robust results has been really limited,” she explained.
At the same time, knowing the populations and how they are doing is important work. Salmon are valuable and cross [international ]borders.
Laurie told me about the Fraser Sockeye, for example—a large and extremely valuable fish. So valuable that a treaty was established between several tribes of western Washington, the U.S. government, Canada, plus U.S. states and Canadian provinces to ensure the fishery is sustainable.
So, tracking matters because salmon matter. They matter enough for international treaties to be enacted.
Fish are tracked in several ways. When it comes to the Fraser Sockeye, acoustic tags are used. These send out unique radio signals, allowing you to identify individual fish. The drawback is you need receivers close enough to hear the signal.
“The continental shelf in some areas is 30 miles wide. That is a lot of real estate,” Laurie proclaimed.
Another option is to use satellite tags. A benefit of satellite tags is that you can see where the fish is, as well as other data like temperature, pressure, and depth from anywhere. The drawbacks are that you must get the tag back to download all the data and, because of the size of the tags, only older adult fish can carry them.
Laurie told me about a study using satellite tags where researchers were getting a slightly elevated constant temperature reading from their chinook for a long period of time.
“What they think is that salmon sharks were consuming these Chinook,” Laurie laughed. The constant temperature was recorded from inside the digestive tracks of the salmon sharks.
Eaten
A break in the trees brightened the path as we reached a high point in the trail. Though the sky was overcast with clouds, the light from the sun cast a dim reminder of its existence through the gray shroud.
Laurie shifted the conversation back to her work on the high seas. This is where things get even more murky.
Laurie started by talking about her work detecting salmon predators on the high seas.
“It is really hard to figure out,” Laurie stated. “It is hard to tell who is doing the predating and when…. Are they [predators] only getting the small fish [salmon] or the sick fish [salmon]?”
In 2019, 2020, and 2022, Laurie and her team did an extensive study of salmon predators using eDNA and didn’t find many.
eDNA is a newer technology, where water samples are gathered and sent into a lab to be tested for the DNA of species of interest, like salmon predators. Because organisms are constantly sloughing off DNA, this is a good way to gauge the presence of a species even when it is not caught in nets.
“We found a couple of predatory salmon sharks and a couple of fish, lancetfish, and daggertooths, that eat strips of salmon…,” said Laurie.
“They aren’t here. We are not catching them in the nets or detecting their DNA.”
Starving
So, what is going on?
Another “arm-chair hypothesis” is that the salmon are starving during the winter. Salmon that don’t get fat over the summer don’t survive onces winter arrives. This would be especially important for small fish because they can’t store much energy. Laurie and her team tested this hypothesis.
“We get out there and ocean age 1 fish are going great, but 2s and 3s are not looking great,” said Laurie. “They are really skinny.”
They took blood samples of the fish to test for Insulin Growth Factor (IGF)—a chemical that signals healthy growth in fish. As expected, fish that were in the ocean for 1 year, have high levels of IGF.
But those in year 2 or 3 had either really high levels or really low levels. They also had green gallbladders—a sign of starvation.
“What’s going on?” asked Laurie.
It is still unclear.
“You answer one question,” Laurie smiled, “and you generate five.”
Do We Stay or Do We Go
Not all salmon spend a lot of time in the ocean, however,“it depends on the species”—a statement I heard a lot from Laurie.
Chum and sockeye are really the only ones with an extended high seas stay.
“What we think happens is they spend winters in the Gulf of Alaska and move into the Bering Sea in the summer until they are ready to come home.”
“Others are only a year,” said Laurie, like Coho.
Then there is fall chinook…
“Fall chinook stay on the continental shelf,” said Laurie. They travel back and forth along the coast for years before returning.
Every species has its own way.
“What is really cool is the whole idea of these chum salmon ages 2 and 3 being skinny. All different stocks are together in the Bering Sea.”
Bang for your Buck
Laurie and I reached our turn-off onto a mountain biker trail. Steep and a little slippery, we both carefully navigated our way down the path.
Laurie pointed out a patch of slippery jack mushrooms as we passed by.
“People do eat them,” she noted, but their slimy appearance didn’t appeal to either of us, so we trod on.
“Anyway, there is all kinds of really cool stuff we are finding being out there [at sea],” Laurie proclaimed. She had a knack for transitions. “It is also really expensive… 32 days at $30,000 per day.”
With that sort of price tag, a lot of work happens before these expeditions to plan and prepare. Using freshwater data and developing hypotheses are vital steps to take beforehand.
“The idea is we are trying to get the most bang for our buck…” Laurie explained. “Using the information [from other sources] so when we are not out there, we can still understand what is going on.”
Food for Thought
While we were talking, suddenly Laurie made bee-lined it off the trail—a massive burnt orange-colored lobster mushroom was growing just off the trail.
“Wow!” Laurie exclaimed, “I don’t think I have ever seen this large a lobster. These are one of my favorites!”
Unfortunately, it was a bit too old and soft to take home and eat, but we took a picture of it to commemorate the find.
“Still cool…” Laurie said as she put it down on the mossy ground.
My mind turned to food, I asked—“What are they eating?”
“Depends on the species,” said Laurie.
Hmmm, that sounds oddly familiar.
“Sockeye and Pink salmon eat low in the food chain—a lot of zooplankton.”
Sockeye’s red flesh is a result of carotenoids from zooplankton being incorporated into their tissue.
“So, the chum are famous for eating a lot of gelatinous stuff,” Laurie continued, “like jellyfish and evolutionary dead ends, like tunicates, they tend to like.”
“Coho, Chinook, and steelhead start with zooplankton and graduate to larval and juvenile fish and squid.”
Laurie with a massive lobster mushroom
It’s Getting Hot in Here
Soon we were off the biker trail and on another gravel road. We passed by some salmonberry shrubs—“any connection there?” I asked, referring to salmon.
“Nope, they just look like their eggs,” said Laurie. That’s what I thought, but worth an ask.
We passed by some more possible chanterelle spots, but only picked one more immature mushroom.
We climbed up onto a small, forested hill next to a creek to check for chanterelles. The hill was dense, shaded, and cool.
While we foraged around, I asked Laurie what she thought the underlying issues were for salmon success. Does it come down to getting enough food?
Though she agreed that food was a big part of it, she was quick to point out that it was probably not just one thing, but rather a host of interacting factors.
High ocean temperatures, for example, impacts many of the other factors associated with salmon success, including food availability.
“The ocean absorbs 90% of the excess heat that we have been putting into the atmosphere,” Laurie stated. “Climate warming is really ocean warming. Even below 5000 meters, it is getting warmer.”
Ocean warming is a factor that cannot be ignored.
Beaver Believers
A murky creek slogged along a the bottom of the forest.
“That is great coho salmon,” said Laurie. “They love side channels in the winter.”
Coho salmon are Laurie’s specialty, having studied them more than any other species. Though a coastal species, they spend a lot less time in the ocean than other species—only a year, though some males may only spend six months—and more time in freshwater.
I asked Laurie if she could tell me anything else about coho that makes them unique. Her response—beaver.
“Coho benefits the most from returning beavers,” said Laurie. “They really do well with beaver ponds.”
Beaver are what are called ecosystem engineers—they transform bottomlands, creating ponds pools, and wetlands. As Laurie put it, “They create “killer coho habitat.”
Laurie told me about early coho research she did in 1987 in Alaska. They would follow the coastal streams up, stopping at each beaver pond to catch count, measure, and weigh coho. Even five beaver dams up, they were still catching coho.
“Coho were flourishing in these beaver ponds,” said Laurie. “They know how to get through the dams.”
Young steelhead and spring chinook love riffles and high mountain streams. Not coho. They like low-gradient streams with connected floodplains.
And of course, they love beavers.
Own up
However, good coho habitat is not easy to come by, as many of the places coho and beaver enjoys, humans like as well.
As Laurie and I popped back onto the gravel road to continue our journey back to our cars, I asked Laurie if there was anything people could do to help coho and other salmon species.
“The biggest thing is just taking ownership,” said Laurie. Understanding that everyone can be either part of the problem or part of the solution is an important first step.
Next, get involved. Laurie suggested participating in local watershed counsels and estuary conservation groups. A lot of times these groups will have opportunities to give back, including planting native vegetation.
Beyond this, “there are easy things you can do,” Laurie exclaimed—“don’t pour oil down the storm drain… think about what you are going to have in your yard…,” she suggested for example.
Reducing pollution and creating natural filters that slow water, are both helpful to fish. High flows can scour out salmon nests, called redds, and carry silt that smothers salmon eggs.
Pollutants can sometimes accumulate in salmon in high concentrations, reducing their ability to fight off disease and sometimes killing them outright before they can spawn. Laurie mentioned a tire preservative that has increased pre-spawning mortality in salmon.
“Even in high seas, they [salmon] have detectible levels [of pollution],” said Laurie.
Sea Legs
Laurie and I continued to discuss the challenges facing salmon as we hiked the gravel road, a better option for salmon than pavement.
We passed by a newt that was exceptionally skinny. Could it be feeling the same strains as salmon feel with winter coming on? I wonder.
I could see the gate ahead of us when I asked Laurie about what it was like to work on the high seas.
“Some days, I think, I can’t believe I am getting paid to be out here,” she smiled, “Other days, I think, they are not paying me enough.”
Laurie has been going to sea for the last 30 years with several weeks on the boat each time. That is a lot of hours clocked on a moving vessel. The seasickness and tight quarters get to you at times, but then there are moments of pure joy and wonder.
Sauté
Soon we are back to our vehicles. We stood and chatted for a few more minutes about lamprey and the vastness of the ocean before we decided to part ways.
As I began to walk off, Laurie gave me one more piece of advice—“Cook them in a dry pan,” said Laurie, referring to the chanterelles, “medium heat.”
And with that, I migrated home. Fish, fungi, forest, and me—we are all connected.
Laurie Weitkamp is a Research Fisheries Biologist with the Northwest Fisheries Science Center since 1992.
About 15 million years ago basaltic lava released from fissures in northeast Oregon and southwest Washington poured through the Columbia River basin, traveling across the Pacific Northwest. Collectively these flows are known as the Columbia River Basalts.
What is perhaps most intriguing is just how far some Columbia River Basalts traveled. Flows can be found in locations as far afield as Silver Falls State Park, for example. Other flows traveled hundreds of miles from their origin through the Coast Range mountains to the Pacific Ocean.
Seal Rock State Park is the site of one such flow—making it a premier location for geology enthusiasts.
So, when I reached out to Sheila Alfsen from the Geological Society of Oregon Country for a hike and interview and she suggested we visit Seal Rock, it was met with a resounding “yes! “
Circuitous routes
I met Sheila in Philomath so we could drive to the coast together and talk geology along the way. As we headed out, she told me a bit about her background.
Sheila’s path to geology was a circuitous one.
She started out as a volunteer and teacher’s assistant at her own children’s schools where she realized she had an interest in and a knack for teaching.
Then, when state requirements insisted she go back to school for her job, her mind and life path were changed.
“My first class was oceanography,” Sheila gushed, “and the first thing we talked about was plate tectonics…This was everything I wanted to know. I was hooked on geology after that.”
Soon enough, Sheila had earned an associate degree, and later a Bachelor’s in Geology and Spanish, and a Master of Arts in Teaching (MAT).
She started teaching high school science and eventually moved on to teaching college courses, some with her mentor, Bill (William) Orr.
Sheila found her passion—teaching geology.
“In Geology, you aren’t just talking about the rocks, but what they tell us about the history, and therefore, future of the planet. In Earth Science, you also talk about the oceans and atmosphere,” Sheila explained—It is all the Earth Systems.
“I can teach basic principles of physical science within the context of earth science.” Everything has a geology connection.
Highway 20
Our first stop on the way to the coast was Ellmaker State Wayside off Highway 20. Here, Sheila laid out a plan for the day and gave a bit of background on the road we would be following to reach Newport.
Several decades ago, the State Department of Transportation attempted to reroute the highway. Back then, the highway was routed through Eddyville where it followed the Yaquina River on windy roads that not only made the drive to the coast longer but more hazardous.
So, the State hired a construction company to cut a new route through the coast range. But problems ensued. The land was unstable, and landslides became a huge issue.
“Basically, they didn’t consider or understand the geology until they already had a lot of problems,” Sheila explained.
Their oversight came at a high cost. By that time, the first company hired had gone broke and a new construction company was brought in with more geological expertise.
“It took 10 years later and over double the budget to get it done,” said Sheila.
Ellmaker State Wayside off of Highway 20
Structure
Sheila and I hit the road again to see just what exactly had thwarted the project. Turns out you can see the problem in the rocks.
As we drove up the highway, Sheila pointed out roadcuts, as we passed. The rocks in the roadcuts were light colored and dipped to the east as we headed up the pass. Later, a bit further up the road, the layers were arranged nearly horizontally. Then, we reached a spot where the rock layers had turned—dipping westward toward the ocean.
Here we pulled over to take a closer look.
Sheila explained that the reason that the highway road project didn’t succeed is that from the start they didn’t pay attention to the geology—specifically, the structure of the rocks.
“When we say structure in geology,” Sheila explained, “we are talking about how the rocks are folded and how they are positioned.”
She went on “Geological structure is how the rocks are put together. It makes a big difference.”
The structure we were observing as we came over the Coast Range on highway 20 is what is called an anticline.
“An anticline is an arch,” said Sheila “and this is one limb of the anticline,” she pointed westward, “and the other way is the other arm.”
Sheila went on to explain that this giant arch was also plunging—dipping to the north.
“Pressure from this direction,” she pointed west again, “from the Juan de Fuca plate, creates the anticline.”
The Juan de Fuca plate is the current tectonic plate that is subducting (going under) the North American Plate just off Oregon’s coast. However, according to Sheila, there is also pressure from the Klamath Mountains to the south that has resulted in a “rotation of the whole coast range”—this is what makes the anticline tilt to the North. This is why pieces of rock were breaking off and sliding onto the road, inhibiting the progress of the construction.
Sheila demonstrates the shape of an anticline.
Tyee Formation
We got out of the car to get a closer look at the rock layers themselves.
As we stood there talking, a police car pulled up to see if we were okay.
Sheila laughed, “Just a little geology lesson,” she told them, before inviting them to join us. They declined, but I got the sense that this was not the first time Sheila has made such an invite.
“This rock is the Tyee Formation,” Sheila described as we looked across the highway at the tilted layers.“This layer of rock is famous,” she went on, “It goes all the way down to the Klamath Mountains.”
The Tyee Formation is comprised of sandstone and shale, formed from sediment that was deposited in a large underwater delta some 45 million years ago. There was no Willamette Valley or Coast Range at the time, just a gigantic bay. The Klamath Mountains were already in existence and shedding sediments into the bay to form the delta.
“The delta was huge and went all the way out northward to about Dallas,” described Sheila. I tried to imagine Oregon 45 million years ago, missing a good quarter of its landmass.
Eventually, the delta turned to rock and was folded and lifted into the Coast Range, powered by the subduction of the Juna de Fuca plate—a process that continues even today.
Turbidity Currents
Sheila suggested we walk closer to the roadcut to look at the rocks of the Tyee more closely.
She explained that when the sediments from the Klamath Mountains would fall into the bay, this resulted in “turbidity currents”— a sudden flush of sediment and water rushing off the continental shelf before settling into distinct layers.
These fast flushes of sediment became the layers of rock that make up the shale and sandstone of the Tyee formation. The sandstone layers in the rock formed from quickly settling sand, and turned into thick, light brown colored layers of sandstone. Clay, on the other hand, “takes a long time to settle out.” These clay layers presented themselves as dark gray, incised bands in the roadcut.
“One layer of sand and one layer of clay above it is one event,” Sheila pointed out. “This is what the Coast Range is made of.”
Sheila pointed out the shiny flecks that glittered in the sandstone layers. “Muscovite,” she called them, “from the Idaho batholiths”—a clue that when the Klamath Mountains were first accreted, they were near the Idaho border.
The Tyee formation up close.
A Closer Look
Sheila soon began to poke around, digging into the roadcut rocks.
“If we are lucky,” said Sheila, as she pulled a rock from the base of the loose shale layer, “we will find little trails of marine organisms.”
You see, between each turbidity current, the organisms that are living and feeding on the sediment before they are wiped out by the thick sequence of sand that suddenly gets dumped on them. Their fossil remains can often be observed as trails in the sandstone and can be used to date the layers.
Sheila and I continued to pick at the roadcut and examine any loose pieces of rock that came away easily. The shale broke off in thin layers, while the sandstone felt gritty and rough.
I held a piece of rock up to my eye with a hand lens to see the shiny flat muscovite mineral amongst the grains of tan-colored quartz and feldspars.
“A geologist sees things. When you learn about the geology you look at the world differently and it is beautiful.”
Tyee sandstone with fossil trails of marine organisms.
The Road to Jump-off Joe
Sheila and I hit the road again. We were going to make one more stop before heading to Seal Rock—a place called Jump-off-Joe.
After another 30 minutes of driving through the Coast Range, we reached Newport and the Pacific Ocean. We drove North a bit on Highway 101 before veering off onto a side street and pulling over in front of a roadblock and a parking lot with an oceanfront view.
Just past the cliff edge, you could see an old building foundation in disrepair, as the land around it had subsided and begun the process of crumbling into the sea.
As we stepped out of our cars for a closer look, Sheila laughed at a sign on the adjacent hotel that boasted about its “ocean views.”
“This building was a football field away from the edge,” said Sheila, thinking back to her last visit. “The view is getting more and more exciting,” she snickered.
“Coastlines are unstable,” said Sheila. A lot of the rock on the coast is layered sedimentary rock and “some are inherently unstable.”
The fact that someone tried to build in this location was ludicrous to Sheila.
“Immediately it started slipping,” said Sheila. “Yaquina Head in the north, to the opening of the estuary is all landslide area.”
Time and the elements had really taken a toll on the abandoned structure. Graffiti covered large portions of the dilapidated foundation. Signs warned people to stay back.
It was all a bit ominous. We kept our distance from the edge.
Derelict abandoned building at Jump-off Joe
Sandstone Arch
Then, Sheila pointed to the right of the crumbling foundation, a small sandstone mound stood just below on the beach. Another sign of erodibility and instability of the rocks that make up much of this part of the coast.
“Back in the late 1800s or 1920s that was an arch,” said Sheila pointing to the small, but visible sea stack. “It has been eroded.”
The location of the arch was once referred to as “Jump-off Joe,” apparently because the cliff down to it was steep. It was quite the site to see back in the day, as evidenced by a quick google search.
Now, it was hardly an attraction, having been weathered down to a remnant of its former self.
Of course, not all the rocks on the coast are as suspectable to erosion and weathering as much of Newport Bay. Yaquina head, for example, just visible to the north is made of basalt—a much more resistant rock.
“That is why those are points out there,” reasoned Sheila. In fact, basalt rocks make up much of the Oregon Coasts’ headlands.
But where did all this basalt come from?
I was about to find out.
View of the remnants of Jump-off Joe
Sea Stacks
Sheila and I took off again for our final destination—Seal Rock State Recreation Site.
We arrived around lunchtime and stopped for a quick picnic lunch at a table just behind the bathrooms.
After lunch, we followed the paved trail back up through the twisted shore pines that led out to the Seal Rock viewpoint. From here, sea stacks of various sizes jet out of the ocean in a curved line.
“We call this a ringed dike because it forms a ring shape,” said Sheila. “What used to be a low space fill with lava, and the stuff around it erodes away,” she explained.
Elephant Rock
The largest of the rocks—a massive rock towering structure—is known as elephant rock.
“Elephant rock is what we call a sill,” said Sheila, “in igneous geology, a layer of lava that squeezes between two layers of rock.”
“In this case, the lava didn’t intrude between the layers, it just fell into the soft sediments of the coast and re-erupted,” Sheila backtracked, So, “not technically an igneous sill…but it is basalt.”
Basalt—a hard and resistant rock. Waves “eat away at sandstone,” but basalt, not so easily.
“You can see the cave under the rock, to the right,” said Sheila as we started further down the trail that leads to the beach. “It is sandstone. It is easier to eat away.” A small cave carved into sandstone cliffs to our right.
Just like at Jump-off Joe there are signs that warn people not to walk on these cliffs. Just like Jump-off Joe, the area is unstable.
Sandstone to the right with basalt to the left in the distance at Seal Rock State Park
Cobbles
The trail eventually petered out as we neared the beach. We carefully clambered over rounded rock cobbles that had been turned by the waves.
“This is nicely polished basalt,” said Sheila as she picked her way down.
Basalt, Sheila explained has cracks in it that develop when the lava cools. The columns of elephant rock are a great example.
“It is easy for the waves to break it up,” remarked Sheila.
Basalt cobbles.
Magnetite
After some careful maneuvering, we reached the beach and headed south, following the ocean’s edge where the sand is firm. Soft gray-colored sand lay underfoot, but Sheila was on the hunt for something darker.
“If you look at the beach, have you seen areas with dark sand?” asked Sheila. “That is magnetite.”
Magnetite, she explained comes from weathered basalt. Magnetite is a dark-colored mineral made of iron and magnesium—making it magnetic. It is heavy and often accumulates in areas.
“Near stream you see it,” Sheila advised. She had seen a thick layer of it on previous visits to the beach and was curious to see it again.
“Here is magnetite,” said Sheila a few moments later—though not the band of magnetite she was hoping to find. Black sand lay in a rippled pattern on the otherwise pale-colored sand.
Magnetite on sand.
Dynamic
“Here we are watching the pattern that develops in the sediments,” said Sheila.
She went on to explain how sediments are pushed up on the beach at an angle by the surf and then fall straight back down the beach so that they constantly are moving along the shoreline.
“A coast is a dynamic place, always changing,” she affirmed.
The magnetite pattern was just one sign of constant coastal change.
A Lava Story
Sills, dikes, cobbles, and magnetite… we headed toward the far shore and crossed a small creek. It was time to get to the main event. Where did the lava come from?
“This is the southernmost extent of the Columbia River Basalt,” said Sheila.
The Columbia River Basalt, as mentioned earlier, are lava flows that originated from fissures in eastern Oregon and Washington some 15 million years ago.
“They made their way through the Cascades, down the Willamette Valley, and as far south as Salem Hills,” said Sheila.
In fact, the Salem Hills are Columbia River Basalts—“they are just coved with vegetation,” explained Sheila.
“A typical flow was 100 ft thick,” Sheila described. “Imagine a wall of lava that is one hundred feet thick and flows like syrup.”
Remarkably the flow stayed liquid as it traveled all the way to the coast. This is different than one might expect especially if you have seen a Hawaiian eruption. Sheila described seeing a lava flow in Hawaii cool right before her eyes.
In the case of the Columbia River Basalts, there is “so much lava, the outside will crust over, and it will break through its own crust and keep going,” Sheila described. “It could advance 3-4 miles per day.”
According to Sheila, the basalt rocks we were seeing were Wanapum basalt, the youngest of the Columbia River Basalts, specifically the Gingko flow.
Final Contact
By now we had made our way over to the sandstone and basalt cliffs opposite the ocean. Here, we passed by what looked like a small black stone wall jetting out of lighter-colored sandstone.
“It was probably soft sand when the dark lava intruded but now it is sandstone,” explained Sheila.
“This is part of the ring dike,” said Sheila, “a crack that is filled with lava.”
Dark basalt lava intruding on sandstone.
We saw more cobbles of polished rock before reaching the far end of the ring dike.
“Basalt is here,” said Sheila pointing up at some heavily fractured black rock overhead. “And the contact between the basalt and the soft sediments,” she pointed to a deeply eroded area below the rocks where thin ribbons of rock layered together.
“Looks as fresh as it did when it cooled 15 million years ago,” she exclaimed with a smile.
The far end of the ring dike.
Tracking Flood Basalts
At this point, Sheila and I turned to retrace our steps. But before we made it back very far, we stopped for a quick geology lesson and big-picture discussion on the basalt flows.
“Coastal provinces are kind of a collage of everything that has happened inland,” said Sheila, as she traced a sketch of Oregon into the sand.
She began pointing out important landmarks… “the Columbia River, Cape Blanco…”
“Cracks opened over here and issued lava,” she pointed up to the northeastern part of the state. “Most of it came down the Columbia River.”
The Columbia River used to be further south in what is now known as the Columbia Plateau, she explained, but it got pushed up north as the lava flowed through.
“Then when it comes to Portland and the Willamette Valley,” we moved further down the map, “it makes up the Amity Hills, Eola hills, and Salem Hills.” Again, these would have been low points, or depressions at the time.
“We find it in the Molalla River in what used to be river valleys,” she continued, and in places like “Silver Falls State Park.”
“Then we see it out here and in the Capes all the way as far south as Seal Rock,” she concluded.
Sheila drawing Oregon in the sand.
A Gap
But there is a problem—a gap if you will. There is not a clear sign of Columbia River Basalt flows through the Coast Range Mountains. How did they make it all the way to Coast near Newport?
This is where Sheila comes in. She has made it her mission to find Columbia River Basalts in the Coast Range Mountains—to trace its path to the Ocean.
Now there is a lot of basalt in the Coast Range Mountains, but the problem is “the chemistry doesn’t match up.”
“A lot of it is Siletz River Basalt,” Sheila said as we restarted our walk back.
Siletz River Basalts are part of a massive igneous province that formed in the Pacific Ocean before accreting to North America beginning about 50 million years ago known as Siletzia or the Siletzia Terrane. This exotic terrane became the foundation for the Coast Range but is also visible in various locations in the Coast Range.
According to Sheila, Columbia River Basalts have “higher silica than most basalt” and each flow or unit has a specific chemistry. She has collected samples at various promising locations in the Coast Range but has yet to find a match.
Perpetual Teaching and Learning
Sheila and I soon recrossed the creek we had waded over earlier.
After we crossed, I asked Sheila to tell me about one of her favorite places on the Oregon Coast. She had mentioned Cape Perpetua earlier and I wanted to know the story.
“Cape Perpetua was a personal thing,” started Shiela. “ I was studying oceanography and looking out at the ocean.”
She could see the waves breaking below her and she realized she could calculate how far apart each wave from another using known distances, like the road. The distance of one wave to another where they start to break tells you the depth of the water at that location.
“It came to me,” she went on. “I really love this. I want to do this.”
Sheila paused.
“That was 25 years ago. I haven’t tired of it.”
We continued our conversation passing through the creek, back up the basalt cobble, and up the paved path to our cars—and Sheila never tired.
And you know what? Neither did I.
Sheila Alfsen is a geology instructor at Chemeketa Community College, Linn-Benton Community College, and Portland State University. She is also a past president and program director of the Geological Society of Oregon Country in Portland. Sheila earned d Bachelor of Arts from Western Oregon University for Geology and Spanish before going on to get an MAT from Western Oregon University.
Oregon’s side of the Columbia River Gorge is known for its steep cliffsides with cascading waterfalls, including touristy Multnomah falls. Hike up any of the creeks and rivers from the Columbia and you are sure to encounter a waterfall or two or three. Lush forests, gorgeous views of the Columbia and nearby mountains, and heart-pumping climbs, make a visit to the region a popular choice for Portland area hikers.
However, there is more to the region than stunning scenery. The Columbia River Gorge is geologically unique. It cuts through one of only a relatively few flood basalt provinces in the world. In addition, the area has been sculpted by the Columbia, and, most profoundly, by the Missoula Flood events—also relatively rare glacial outburst flood events that help define the region.
To better appreciate the unusual geological history of “the gorge,” I met up with Jim O’Connor from US Geological Survey at the Horsetail Falls Trailhead for a short hike up to Triple Falls.
Quadrangle by Quadrangle
Having not visited Triple Falls in a long while, when I arrived at the trailhead to meet Jim, I was more than ready to explore the trail through his fresh geological eyes. After gathering our gear, we headed across the Columbia Gorge Highway to the Oneonta trailhead to begin our climb up to the falls. As we got started, I asked Jim to tell me about where we were.
Jim explained that the USGS has been mapping the Columbia River Gorge for the past 10 years—quadrangle by quadrangle. A quadrangle is roughly an eight-by-fifteen-mile area.
“In the Gorge, from the Sandy River to the Deschutes River there are probably about twenty-five quadrangles that touch the Columbia River… Right now, we are in the Multnomah Falls quadrangle.”
Most of the mapping has been done, but only a few quadrangle maps have been published so far. The Multnomah Falls quadrangle was mostly mapped about six years ago but publication awaits final review and layout.
I asked Jim why there was such a push to map out the Columbia River Gorge Corridor.
“There are a bunch of reasons for that,” he responded.
One reason, Jim suggested, was to simply tell the history of the place. The Columbia River Gorge, as mentioned early, is a relatively young flood basalt province—built up layer by layer of thin, fluid basaltic lava flows, as you see in a Hawaiian style of eruption.
“There are probably some 50-individual basalt flows as part of a major eruptive episode that occurred mainly around 16 million years ago,” Jim described.
“Originating from fissures in SE Washington, NE Oregon, and Idaho,” he continued, “these flows covered 200,000 square kilometers. Covering much of Eastern Oregon and Washington; flowed through the Cascades, and many flows made it even to the Pacific.”
Other reasons include understanding “the causes and consequences of a large igneous province” and “the history of the Columbia River,” along with the paleogeography and topography.
This Rock is Not Like the Other
One goal of the mapping is to distinguish the different flows apart and track their individual extents.
“They all look the same,” explained Jim. “If we bang on the rocks, we look at fresh faces, sometimes you can see minerals that help tell them apart, but really the only reliable way to tell them apart is geochemically.”
That means heading out into the field and collecting samples of rock.
Jim described hiking up and down the trails and in between with a rock hammer and sampling rocks, being sure to mark each rock’s location. The samples are then sent in for chemical analysis and lines are drawn on the map that traces each flow.
The work is very physically taxing, but the best way to get the job done. Hazards, regulations, and other limitations make it difficult to collect samples during much of the year, so much of the fieldwork is limited to September and October.
With all that in mind, Jim suggested that this sort of mapping would be mostly phased out—probably in the next few decades.
“The mapping we are doing now is probably the last being done ‘boots on the ground’ because it is hard and time-consuming,” said Jim. “Technology is going to develop and remote detection will happen”
In fact, a lot of the technology necessary already exists. Most topographic lines are already drawn using remote sensing, for example. There are even devices (currently used on Martian rovers) that can analyze rocks on the spot. Though Jim said that Columbia River Basalts’ differences are too subtle for the current iteration to work.
“Probably next century [mapping work will be done] with drones,” laughed Jim.
Jointing/Patterns in the Rocks
Once across the road and started hiking up the trail, we were able to get a closer view of the thick layer of rock with a jagged, angular texture.
“What we can see here is one thick massive flow,” Jim explained pointing at the massive rock walk. Jim described the fracture pattern as “Hackly” or “brick bat”—terms that I had not heard but essentially described the sharp and even pattern in the rocks. He also called the area an “entablature” zone—the name for a zone of basaltic lava with this sort of irregular fracture pattern, or ‘jointing’.
“Sometimes the jointing will be in columns,” Jim added—another typical jointing pattern of basalt that reminds me a bit of a bundle of pillars.
He went on to explain how the different jointing patterns develop while the lava cools in place. Jim used the analogy of mud cracks—like mud, it cools (or dries) from the outside in, shrinking and breaking into often beautiful formations.
“Some flows have distinct jointing,” Jim went on, allowing an astute geologist to tell flows apart.
“This is the Downey Gulch flow,” Jim said pointing back up the large rock face. “It commonly has this thick entablature zone.”
Thick entablature zones like this are often where you find waterfalls, Jim explained—“they hang together better than the columnar zones.” They are also “associated with cliff bands,” he added—the resistant tops or layers found in rocks.
An entablature zone with its irregular fracture pattern.
Other Lavas
I asked Jim if other lavas had jointing patterns as you see with basalt.
“You will see jointing patterns in all lava flows,” he responded. “Even stickier flows you associate with Hood or Helens have all sorts of cooling fractures.”
“…But in basalt flows,” he went on “the jointing patterns are bolder and more distinctive because they flow farther.”
Columns and College
As we continued along the trail—tracing the contours of the cliffside, we passed by a nice-looking column of basalt laying on its side.
As we walked, Jim told me briefly about how he got started in his career in geology and how long he has been working.
“I got my undergraduate degree 40 years ago,” he shook his head disbelievingly.
Graduate school followed as it was difficult to find a job without it, and eventually, he landed a job with USGS.
“Look,” I pointed to another column laying on its side.
“A perfect hexagonal cross-section,” Jim noted as I snapped a picture.
One of the columns found along the trail.
Making Contact
Jim and I continued up the trail—zig zagging through a rocky cliffside and into the burnt forest. An assortment of shrubs and herbaceous plants lined the path—my favorite, the red thimbleberry, ripe and ready to taste.
However, Jim’s eyes were focused on the rock as we made our way up. He was looking for a particular feature in the rocks we were walking on—a flow contact. An important part of mapping out the area requires knowing when one flow starts and another begins—this is the flow contact.
“It is probably a flow contact up there,” Jim pointed up the trail.
Jim explained that there are many clues to finding a flow contact.
As you reach a flow contact, the rocks look different because the tops and bottoms of flows—as they interact with the surface get gas bubbles trapped in them. This creates a “vesicular” or “bubbly texture,” in the contact zone.
It wasn’t long before we reached the flow contact Jim had suspected from below.
He pointed to the cliff face.
“You can see there is an entablature zone, flow contact, and then columns,” He remarked. “It looks like two flows.”
Jim gestured to the vesicles observed in the rocks where they met in the flow contact zone, as well as a thin layer of weathered rock that lay in between.
This layer is known as a “weathering horizon,” and is another feature of flow contacts.
The tops of many of these basalt flows were weathered during the many thousands of years before the next flow—rain, sun, fire, vegetation growth, and soil formation breakdown the flow top, leaving distinct weathering horizons that were later buried by the next lava flow.
Vesicular rock found near a flow contact.
Geological Unit
Looking at the map, Jim hypothesized that we were at the base of the Downey Gulch flow and moving into Grouse Creek—the name given to a younger basalt flow in the overall sequence.
“What makes a unit?” I asked Jim.
Jim explained that each geological unit shares a similar chemistry and are thought to be close together in time.
“Originally, these flows were defined by their magnetic orientation,” Jim continued.
Basically, he explained, the magnetic field has switched at various points during the emplacement of the lava flows. A magnetometer was used to determine the direction of the magnetic field when the flow was emplaced—during a normal orientation or reversal—the sequence of orientations helped to correlate individual flows from place to place as well as to deduce their timing. These correlated flows were then defined as a sequence of geological units.
“We are walking through a magnetic field right now,” Jim proclaimed.
Unstable
As we hiked, it was hard to ignore the blackened trees standing along the trail. The Oneonta Trail is one of many trails in the gorge that was heavily impacted by the Eagle Creek Fire of 2017.
In general, the gorge is an area “susceptible to rock slides,” according to Jim—only the fire has made it “even worse.”
Fires are impactful, especially a couple of years after the fire. The fire kills the trees that normally stabilize the upper part of the soil. As the roots of the trees begin to lose their integrity over the years, that is when rocks and other debris can come loose and fall.
“We have done a bit of work on how the fire has affected the slope processes in the gorge,” Jim remarked. “It really is important work.”
“In January 2021, a woman was killed at the Ainsworth exit by a debris flow,” Jim confided. “That area has been a constant source of debris flow.”
Signs have been erected throughout the burn area for this reason. When entering a burn area, one should prepare for hazards and know the risks.
Burnt trails along the forested trail heading toward Ponytail Falls.
Columbia River Course
Speaking of water, as Jim and I headed around a bend in the trail, Ponytail Falls came into view. The small falls poured over the basalt cliff into a deep pool below.
The trail took us behind the falls into a cavern where we could get a look at some sediment that was probably present before the lava flow poured through.
“Looks like some sort of floodplain or silty or maybe even a bog,” Jim speculated as he scraped at the baked sediments.
Sediment deposit below Ponytail Falls.
“It is pretty cool to see exposures like this,” he proclaimed. “Paleogeography is what I am interested in… the area between the flows.”
Jim explained how looking between flow deposits can tell you a lot about landscapes of the past. Gravel, for example, indicates a river flowed through—the different sizes of clasts, details about the flow.
One of Jim’s projects is to map out the course of the Columbia River over time by studying these sorts of sediments.
“The Columbia has been roughly in the same place the last 50 million years,” Jim said. But it has wiggled around a bit. Over the last 16 million years the river has been displaced North. In fact, Columbia River Basalt Flows through Silver Falls show that the river came through near Salem during the early phase of the Columbia River basalt flows.
Because the Columbia River system starts at the Continental Divide in the Rocky Mountains, there are a lot more exotic rocks from the east that can be found in the sediments of the Columbia. Mica flakes, mainly from older rocks to the east, are a distinctive component of Columbia River sediment deposits.
The small grain size of the sediment found in the waterfall alcove didn’t show any signs of mica. Whatever stream systems were attached to the body of water that was here in the past must have been more localized.
View looking out of the alcove behind Ponytail Falls.
It’s My Fault
As we walked away from the waterfall, I noticed a large crack in the lava cliff the water flowed over. I asked Jim about it.
“Those could just be from downcutting,” said Jim. As the stream cuts down on the rock, the material is eroded away, and the land is decompressed enough that it may lift and crack.
However, though not likely in this case, cracks can also be formed through faulting. And in the Columbia River Gorge, there are a lot of them.
Jim explained how the state of Oregon is essentially rotating clockwise. The Columbia River is bounded by North trending faults that through rotation are offset laterally, resulting in a collection of strike-slip faults that move land to the west northward.
“Everyone knows about the subduction zones,” said Jim, “but these younger faults are a seismic hazard.”
“One of the main motivations [for mapping the Gorge],” Jim continued, “is to better understand the seismic and other hazards.”
Jim told me about a fault scarp that was discovered just east of Cascade Locks recently. The scarp here is large—five to six feet tall by Jim’s estimation—and would have been the result of a significant earthquake event.
“One idea is that the shaking might have triggered the Bonneville landslide,” said Jim. A landslide that was large enough that it blocked the Columbia River Valley, creating the legendary Bridge of the Gods and the Cascade Rapids.
“We know from tree ring work and carbon dating that the landslide occurred in the 1440s,” said Jim.
With more faults being discovered all the time in the Gorge, the question is when will the next earthquake (and possibly a major slide) occur.
Finding Fault
As we continued away from the falls, I asked Jim how geologists usually identify a fault—are they easy to find?
“There has been a revolution in topographic resolution,” Jim responded. “We can see the landscapes with what we call LiDAR.”
LiDAR works by shooting a laser down from an aircraft that can pick up on the subtle variations in the Earth’s surface.
“More and more of Oregon has been flown for its topography,” said Jim. Now there is imagery of about two-thirds of Oregon, according to Jim.
“It’s like crack for geologists,” he smirked.
Jim also mentioned that it may not always be possible to identify scarps/faults on such steep topography as you find at the Gorge.
“The terrain is so steep,” said Jim, “so scarps don’t last long; things get chopped up.”
Either way, Jim is certain of at least some faults—the nearest being at the Ainsworth exit.
A Room with a View
Jim and I passed by another striking entablature zone, before reaching a junction to the right towards a viewpoint. We decided to stop for a quick detour.
At the end of the short trail are a memorial and a nice view looking to the northeast.
“Well, you can see the toe of the Bonneville landslide,” Jim noted, pointing to a hummocky peninsula jetting out a bit into the Columbia.
“In this area…the uplift has been the greatest,” Jim explained looking out toward the Columbia River. “Everything has arched up 3,000 feet between the Portland Basin and the Dalles.”
Yet, “The river has been at or above sea level the whole time,” continued Jim. “It has been cutting through the whole time… as it cuts through, it undermines the sides.”
Additionally, below the lava flows is the Eagle Creek Formation—a mixture of volcanic sediment from Western Cascade eruptions 20 to 30 million years ago (mya). This underlying material also tilts to the south—giving the Washington side of the Gorge its more gradual slopes compared to Oregon’s steep terrain.
The combination of uplift and a weak, incoherent underlying geology that tilts make the area landslide prone.
“All of that terrain is landslide terrain,” proclaimed Jim, the powerful Columbia rolling past as we spoke.
Columbia River viewpoint with Beacon Rock to the left and other peaks in the distance.
Beacon to the Past
As we looked out at the scenery, Jim pointed out other features from the viewpoint. One of the most prominent being Beacon Rock.
Long after the flood basalts spread across much of Oregon and Washington, volcanism returned to the region in the form of a large volcanic field about 3.6 mya—reaching from the West Hills of Portland all the way to the Deschutes. Cinder cones, lava flows, and shield volcanoes have been identified in the volcanic field, including Larch Mountain in the Columbia River Gorge Scenic Area and Mount Scott in Portland. Though Jim couldn’t point to an exact source of the volcanism, he was fairly certain it was in part related to subduction.
“Beacon Rock is the youngest in the basin,” said Jim—erupting about 60,000 years ago. Once a small cinder cone, much of the unconsolidated material that surrounded its volcanic neck has been washed away by massive ice age floods.
Now a bare rock sits along the northern shores of the Columbia.
Missoula Floods
This brings us to one of the most recent installments of the Columbia River Gorge’s geological story, the Missoula Floods.
Around 20,000 to 15,000 years ago, Glacial Lake Missoula would form as the Cordilleran ice sheet flowed south from Canada creating an ice dam that blocked the Clark Fork River drainage in Montana. Periodically, this ice dam would fail, and flood waters would pour out of Glacial Lake Missoula through Washington and Oregon as it followed the Columbia River drainage.
The effects were dramatic. Scablands were created through much of eastern Washington, as the water tore up the soil and carried it downstream where much of it settled in the Willamette River Valley or was carried out to the Ocean. The gorge played a significant role in controlling the flood flows.
“The Gorge was a constriction or nozzle the floods were forced through,” Jim explained. “It was mainly erosive through here.
Inverted Topography
After enjoying the views and trying our best to identify the peaks on the horizon—is that Defiance or…?—we turned back to the main trail leading deep into the basalt cliffs that make up the Oneonta Gorge.
As we looked up at the steep cliffs, we could see another entablature, as well as a couple of flows. Jim referred to his geological map to see if we had moved into a different flow unit.
“Nope, still Grouse Creek,” he concluded.
However, looking back and up to the top of the canyon walls, Jim pointed out a lava-capped ridge—Franklin ridge, he called it.
Franklin Ridge is the result of a local volcanic center, Jim explained, erupting somewhere around 1-3 million years ago. At that time, the lava flow was down a valley that led to the Columbia River. But since the lava flow was uplifted and the surrounding rock eroded away, the lava-filled valley bottom “is now a ridge.”
“A topography reversal,” Jim called it, or inverted topography—essentially the low points become the new high points.
“Kind of cool,” Jim remarked.
Franklin Ridge is an example of inverted topography.
Water
Jim and I continued to make our way on the dry dusty trail. Soon we passed by a moss-covered basalt rock face dripping with water—not an unusual sight to see.
I asked Jim about what we were seeing.
“It is probably emerging at the top of this flow,” said Jim—at a flow contact.
“Water moves slowly through solid flows,” Jim explained, “seeping through the cooling joints. It moves more rapidly between flows.”
This is visible as wet stripes in the contact zones between basalt flows, especially in the arid east where the moisture contrasts well against the dry rock. You can literally see where the moisture is in the rock, according to Jim.
Transportation of water through the Columbia River Basalts varies a lot but can be rather slow—sometimes taking thousands of years to emerge at a contact zone.
“Some of the water in the layered basalt, especially in the east, certainly dates from the last ice age,” said Jim.
Understanding the basalt stratigraphy for the purposes of managing water resources is another reason mapping the Columbia River Gorge is important work. Knowing the flow contacts and the connections to each local aquifer system, are all part of ensuring water use is sustainable over time.
Lower Falls
Jim and I cruised past another flow top—“See how vesicular it is?” he questioned.
Then, we passed an entablature holding up the cliffs before passing over a deep gorge and reaching the lower falls.
Water ran smoothly down a narrow slide of lava littered with tree trunks—the water cut deeply into the erosion-resistant basalt to form a V-shaped valley.
The Lower Falls reminded me of just how powerful water is as an erosive agent. The canyon walls were high above us. Oneonta Creek had done a fine job cutting down.
Lower Falls careening over basalt rocks.
Ortley Flow
After climbing a bit deeper into the canyon, we passed by a wilderness sign and an unusual-looking rock face. Jim checked his map and sure enough, we had reached the base of the Ortley flow.
Jim pointed out the differences in morphology that were clues that we were entering a different flow unit.
“One thing that is our first hint is it is oriented sideways,” said Jim. “Cooling fronts are coming from the sides.”
Jim explained that some of the Ortley lava flow must have been locally channelized—flowing through an old river or creek bed.
Vertical columns form slowly as they cool from the bottom and top. These sideways columns were the result of multiple cooling fronts on the sides of the channel.
Columns oriented sideways; part of the Ortley flow.
The bottom of the flow also looked different. Rounded blobs of broken glassy rock were visible, a.k.a. pillow basalt. As Jim explained, when lava encounters water it will either brecciate (break apart into angular fragments) and may form “pillows.”
“Hyaloclastites,” said Jim, referring to the glassy rocks. “The pillows are direct water features.”
Pillow basalt on the trail. A result of the interaction between lava and water.
Interflow Zone
We walked on up the trail. Only we hadn’t made it far when Jim stopped suddenly.
“I am just noticing some rounded clasts,” he said. “It is making me think there is probably an interflow zone with gravel coming out of it.”
This was Jim’s bread and butter. He started digging through the rocks with intense focus.
“Is there anything other than basalt?” he wondered. “Any hint of the Columbia?”
The rocks were large and rounded, embedded in a “really weathered matrix.”
Interflow zone with a really weathered matrix.
Jim speculated that the interflow zone was probably a steeper tributary to the Columbia that was back flooded when lava came pouring through the Columbia River drainage.
“This might be related to the pillows we saw earlier,” Jim hypothesized.
He continued poking around in the matrix for loose material until he found a rock that he thought “looked different.”
He picked it up with the thought of cracking it open for further examination.
“Why did you pick that one up?” I asked, curious about what he was seeing.
“It is light colored,” he said with a smile.
It was as simple as that.
Jim and his light colored rock.
Triple Falls
Eventually, we reached Triple Falls—a three-pronged falls flowing over Columbia River Basalts—and our destination for the day. We wondered at the strange flow pattern of Triple Falls and marveled at its beauty.
Triple Falls is classified as a segmented waterfall with flows that drop vertically into a large plunge pool below. Each of the segments flows between bulbous volcanic rock barriers. Were these rocks more resistant than the rocks the water poured over?
Just past the falls, we crossed a bridge and stopped for a short lunch break before heading back to our cars.
Boot Prints in the Sand
On our way back Jim and I talked about all sorts of things—from travel to hiking adventures and pet projects—as we retraced our steps.
Eventually, though, the conversation turned back to the geology of the Columbia River Gorge as something shiny caught Jim’s eye.
“This is interesting,” he said reaching down toward the dusty ground. “This is Columbia River sand.”
The light tan color of the earth faintly shimmered as mica flecks in the sediment caught the sun’s rays, Jim explained that the Columbia River mica flakes are large and platy in structure. When light hits them just right, they shimmer.
“Not sure how it got here,” Jim said quizzically. “It could have blown in…or been brought in by the Missoula floods… or it could be coming out between flows.” There was no way of knowing.
Columbia River sand on the trail.
Puzzle
The rest of the hike back went by quickly. Time seems to slip by when you are heading downhill. And before I knew it, we were back at the trailhead saying our goodbyes.
Jim was a lot of fun to hike with. Every time we ran across something new, it was like finding another piece of a geology puzzle.
There is a lot we know about the Columbia River Gorge. Its unique geological history means it has attracted a lot of attention over the years. Yet, there are still a lot of pieces to the puzzle to be found.
Finding those pieces and fitting them together is what geologists, like Jim, do. Offering a glimmer of understanding to folks like me—to help us see the mica through the sand.
Jim O’Connor is a research geologist with USGS. He earned a Bachelor of Science degree in Geology at the University of Washington before going on to earn an M.S. and Ph.D. at the University of Arizona. Jim has been with USGS since 1991 where he has focused his efforts on understanding the processes and events that have shaped the Pacific Northwest.
