Tag: hiking

Hike with a Cell Biologist

View out toward Marys Peak from the top of the hill.

Let’s talk tiny. I mean really tiny. Like, get out your microscope small. I am talking about cells!  You know them, you love them—those little bags of gobbledygook filled with smaller stuff still, with names like endoplasmic reticulum, ribosomes and Golgi bodies. 

Cells are the building blocks of every living thing on the planet. So despite their size, they are kind of a big deal. So big that on a sunny Thursday afternoon I met up Marc Curtis, a cell biologist from Oregon State University, to talk about the small stuff.

The Hike

  • Trailhead: Forestry Club Cabin Trailhead at Peavy Arboretum, Corvallis, OR
  • Distance: 4.8 miles
  • Elevation Gain: approximately 900 feet
  • Details: Plenty of parking at the trailhead. Restrooms available at the arboretum, but not at the trailhead. This hike is part of an extensive trail network throughout the McDonald-Dunn Forest, so there are many options to extend or shorten the hike.

Cell Level Thing

We immediately started hiking uphill from the parking lot along a forest road that leads to Oregon State Universities Forestry Club Cabin, before turning onto the tree-lined trail. As we trudged along several steep sections of the trail, Marc told me about his background. 

Marc was fascinated by cells from a young age. In high school, his father, a Molecular Biologist at the Wistar Institute in Philadelphia, gave Marc a review article on cells and their role in cancer. Marc was hooked. “That just made sense to me, that cell level thing,” he said. “They grow, divide, they talk to each other, they take on different functions and they build the body.”

As an adult, Marc pursued his interest in cells by studying biochemistry at the University of New Hampshire and getting involved in undergraduate research involving cell signaling in the corpus luteum. Later, he moved onto Oregon State University to study cell death, as a graduate student, and eventually cell mutation as a postdoc. 

Grow, Divide, Repeat

Marc has made a career out of thinking about cells, what they do, and how they do it. But cells are so small, invisible to the naked eye. Can we find a way to appreciate cells while on a hike?

A good start is to pay attention to plants. This is where Marc has focused most of his career. 

Unlike humans, plants typically grow throughout their lives—packing on the inches at their tips, as long as conditions allow. Plant growth occurs in the roots and the shoots—where apical meristematic tissue composed of undifferentiated cells grow and divide. Meristematic tissue is also found in the buds and the nodes, the “joints” of a plant. Many different plant tissues and organs can arise from these growth regions, including leaves and flowers.

Marc pointed out the shoot apical meristem on one of the plants we saw along the trail. “It is in there,” he said, directing my eyes to the place where the leaf meets the stem. “That is where you have the undifferentiated cells—the fountain of youth—where new uncommitted cells come from.” 

Marc explained that when these cells divide, they build up from the bottom layer and will eventually differentiate and become tissue, so the cells at the tips can maintain their undifferentiated status. 

Meristematic tissue is found where you see branching on this plant.

Time for a Change of Pace

However, this doesn’t mean these cells remain unaltered throughout the life of the plant.  Because apical meristem divides so prolifically, mutations can accumulate in the meristematic tissue.  Marc studied the process of mutation using meristematic tissue as a postdoc. Mutations are “mistakes” in DNA—a cell’s molecular instruction book—that arise during the replication process or from environmental factors, like UV light. 

Marc was interested in how plant cells are able to bypass mutation so they can continue to grow and divide. Turns out that plant cells are pretty good at this. By maintaining a low level of fidelity during the replication process, cells in the apical meristem can continue their work of supplying the rest of the plant a lifetime supply of—well—cells! This also means there can be 100s of genetic variants in the meristem of one individual plant that can potentially give rise to unique growth forms. Though it seems like this is fairly rare. 

In any event, growth is cellular! So when you see new leaves and flowers emerge in the spring, or look up to the tippy-top of a tree, or notice a new growth pattern in a familiar species—think tiny! Think— grow, divide, repeat! The leaves, flowers, and new growth each year are the result of the microscopic world of cellular division! 

Looking up at the tippy-top of some trees on the trail.

Beauty in Death

In autumn, cells take a turn for the morbid. As Marc and I made our way further up the trail, leaves crunching underfoot, I asked him to explain how cells were involved in the spectacular displays of fall foliage observed during this time of year. 

The process is called autumn senescence—which essentially means a slow, seasonal death. Cells that make up the leaves of deciduous trees start to shut down in the fall in response to changes in daylight hours and temperature. In order to conserve resources, cells “break down chlorophyll and other components,” Marc explained, “leaving carotenoids and other pigments exposed.” Hence, the bright oranges, yellows, and purples. This organized way of dying, allows plants to hold onto difficult to obtain nutrients, like nitrogen, so that later in the spring they can begin to” grow, divide, repeat” once again. 

Bigleaf Maple autumn color (a.k.a. dead/dying cells)

Dead Tissue Eater

However, cells don’t always die in a blaze of colorful glory. Cell death may also be an adaptive defense. Earlier in the hike, Marc talked about his PhD work on a plant that when attacked by a toxic fungus would respond by activating cell death. This might seem like a bad idea at first glance, but by killing off the tissue where the fungi attacked, the plant was able to stave off further damage and prevent the fungus from eating it. You see, this particular fungi was a biotroph, meaning it only consumes living tissue. Dead tissue was entirely unappealing.  

Unfortunately, Marc’s tale has a sad ending. Another fungus came along—a necrotroph, or dead tissue eater—that was able to mimic the biotrophic fungi’s toxin, triggering cell death in the plant. Only in this case, the dead tissue was very appetizing to the fungi. It is a dog eat dog cellular world out there! 

Gall-y

Eventually, Marc and I made it to the top of the Powder House Trail, where the vegetation changed from the Douglas-fir and Big Leaf Maple trees we had spent most of our hike walking through, to a hilltop prairie of grasses and Oaks. Walking amidst the oak trees reminded me of the dozens of oak galls my kiddos and I had spotted amongst the fall foliage on another recent hike in the area. I asked Marc about these odd growths. 

Though he didn’t know a lot of details, Marc did recall that the growth was the result of a parasitic “gall wasp.” The gall wasp will lay its eggs on an oak leaf or twig, usually in the spring. Then, when these eggs hatch into larvae, they release biochemicals that “brainwash” the cells of the leaf or twig into forming a gall. The gall—a growth filled with nutritive cells—envelops the larvae as it forms, protecting and feeding it while it pupates. 

Upon further research, I found that gall shape and structure are unique to each parasite, even between individuals of the same species. And that the growth pattern of galls are so different from normal leaf or branch tissue growth, that “they have been described as new plant organs” with a unique chemical signature. Though it seems there is still more research needed to understand exactly how the larvae control cell growth and division, galls are an impressive example of what I like to call “zombie biology.”

Green Islands

In discussing galls, Marc was reminded of another parasitic relationship that can be observed in the fall—green islands. Green islands are spots on a leaf that will remain green even as the rest of the leaf begins to undergo senescence. Marc explained—the green spots are the result of a fungal infection. “The fungus produces plant hormones called cytokinin which delays senescence.”  This keeps the chlorophyll—the green stuff involved in photosynthesis—from breaking down. Hence the green. This also means the plant’s food factory stays open for business, providing the fungus a continuous supply of sugar. Needless to say, this is a pretty sweet deal for the fungi. 

Green islands on Bigleaf Maple leaves

Wax on, Wax off

As Marc and I meandered along the trail looking for green islands (later we found a few examples), Marc pointed toward a gnarled and twisted tree trunk with peeling red bark straight ahead—a Madrone! 

A personal favorite of Marc’s I walked up to get a closer look. I felt one of the thick, smooth leaves.  “What is going on here?” I asked. “Why do Madrone’s have waxy leaves?” It must be something cellular I thought. 

I was right! “Waxes are secreted by the epidermal cells through the endomembrane system,” Marc replied. The endomembrane system is the machinery in a cell that packages and transports certain molecules, like wax, into the extracellular world. Marc explained, The Golgi probably synthesizes the wax. It is then gathered in vesicles. These vesicles transport the wax to the outer cellular membrane. Here they fuse with the membrane and dump the wax out into the cell wall. And voila—waxy leaves! 

Human bone-building also uses the endomembrane system, Marc shared. Though in this case, the bone cells are spewing out collagen protein—the number one ingredient for bones. Think about it! Our skeletons are made from cells throwing up all day. A fun fact Marc likes to share with his students.    

Waxy leaves on a Madrone tree.

Evolution

Eventually, Marc and I made our descent back towards our cars. On our way down the trail, we chatted about topics ranging from teaching on zoom to plant podcasts. 

Marc was also on the lookout for a liverwort he had been able to identify recently and wanted to see if he could find it again. In addition to several botany courses, Marc also teaches an evolution course at OSU. So with ancient plants on the brain, biological evolution naturally came up as we hiked along. 

Innovation

Like most things, if you haven’t caught on yet, evolution is very much a cellular process. Mutations that occur in reproductive cells, gametes, provide new genetic variation to a population. Meiosis, the development of reproductive cells, does the same by mixing and matching genes so each gamete is unique. 

Of course, there is much more to evolution by natural selection than genetic variation. When passing by a Douglas-fir tree, Marc shared with me his thoughts on the subject. “Bark,” he said, “has a high surface area with all the cracks and creases.” When bark like this evolved it provided opportunities for many other species to evolve on it. “Innovation opens the door for more innovation,” Marc explained. He used the analogy of the internet boom.  Once the internet got started it provided opportunities for online retail, social media, etc. One new idea brought about many more ideas.  Life is similar—a new biological innovation can open up ecological space for new species to emerge. 

Douglas-fir bark with deep ridges.

Listen to a Liverwort

Toward the end of our hike, Marc finally found his liverwort. He pointed out how the “leaf” structure and arrangement was different from that of a moss or any other plant. A difference that Marc had only recently developed an eye for, and I had never considered. In fact, I was pretty sure I have been mistaking liverwort for some other group, like a lichen or moss, my entire life. 

Marc’s liverwort! Check out those “leaves!”

Back at home, I kept thinking about Marc’s liverwort and his thoughts on innovation. And maybe because the world seems so divided, or perhaps it is a personal crisis of faith in mankind, but I can’t help but feel like there is some sort of deeper message here. 

Throughout our hike, the concept of curiosity being essential to scientific work kept coming up. But I think it goes beyond science. We all need to be curious. Open our eyes to the liverworts of the world—not lump them together with lichen or a moss—assuming they are all the same. We need an evolution of the mind! And just like the bark of a tree, innovative ideas will open the mind to more innovative ideas. 

Cells are amazing in their simple mantra—grow, divide, repeat. But it is mutation, change, or innovation—that keeps things moving forward— evolving. 

So, let “new variations” or ideas sink in and become part of your mental framework. If nothing else, you may finally learn to identify a liverwort.

Marc Curtis is an instructor at Oregon State University in the Department of Botany and Plant Pathology. Marc has a Bachelor’s degree from the University of New Hampshire in Biochemistry and PhD from Oregon State University where he studied mutation in plant cells.

Hike with a Wildlife Biologist at Finley National Wildlife Refuge

Looking out at the restored Oak Savannah on the Mill Hill Trail.

When Euro-American settlers arrived in the Willamette Valley of Oregon in the mid-nineteenth century, they encountered a landscape far different from what you see there today.  Historical accounts describe open fields of tall grasses and wildflowers with a few oak trees interspersed.  A biodiverse paradise for songbirds, butterflies, and other species that rely on an open system. Maintained by the indigenous people, the Kalapuya, for centuries—the expansive landscape must have been appealing to many early settlers as well.

Flash forward to modern times—and the Willamette Valley is now a complex of agricultural fields and urban and suburban environs. Most of Oregon’s major population centers, like Portland and Eugene, as well as the state capital, Salem, are in the Willamette Valley. Currently, more Oregonians live and work in the Willamette Valley than in any other part of the state and over 170 crops are grown there. Development has completely altered the landscape. Only about 1% of the Oak Savanna habitat that was once prominent in the area remains. Wetlands, riparian areas, and oak woodlands have all suffered major losses in the Willamette Valley.  

A Few Hold Outs

However, there are still a few holdouts and a lot of effort to maintain and restore what remains of these important habitats. One of the holdouts is Finley National Wildlife Refuge, just a few miles south of Corvallis, OR. And one of the people putting forth the effort to maintain and restore is Nate Richardson, a wildlife biologist for the U.S. Fish and Wildlife Service (USFWS). 

I met up with Nate at Finely to hike the Mill Hill Loop and chat about Willamette Valley habitats and the challenges of maintaining and restoring them. 

Nate Richardson on the trail.

The Hike

  • Trailhead: Mill Hill Trailhead (or Refuge Headquarters)
  • Distance: approximately 3 miles
  • Elevation Gain: 300 feet
  • Details: This is an easy hike. Most people park at the overlook for the display pond. You can also start at headquarters where there is ample parking. However, when this was written, the lot was closed to visitors. There are bathroom facilities within the refuge.

Into the Woods

Nate and I started out on the trail hiking through oak woodlands. Nate pointed out the structure of the forest. There were a lot of smaller, younger oak trees with a few larger oaks and an understory of shrubs—typical of this habitat type. Oak woodland is a priority habitat in Oregon and provides for many species of concern in Oregon, such as the acorn woodpecker and white-breasted nuthatch. Though we didn’t see any during our hike, the Mill Hill Loop is an excellent spot to look for woodpeckers, said Nate. 

A Tale of Two Trees

However, despite the many functioning aspects of the oak woodland we were hiking through, it didn’t take long before we spotted one of its biggest threats—conifers.  Nate explained how Douglas-fir trees grow much quicker than Oregon’s oak species, like the Oregon white oak. Because of this difference, when Douglas-fir inundate an oak woodland, they tend to outcompete the oak by shading them out.

As we continued down the trail, we could see several examples of Douglas-fir trees in direct competition with the oak.  We even saw a few dead oaks as a result. 

A Douglas-fir tree in competition with an Oregon white oak.

Managing with Fire

In the past, conifer and shrub species were kept in check by the indigenous people of the Willamette Valley—the Kalapuya. For hundreds of years, the Kalapuya used fire to maintain the open habitats of the Willamette Valley for forage and hunting. Without fire, woody species have encroached further and further into the foothills of the Willamette Valley, such that much of the oak habitats, especially upland prairie, has been all but eliminated. 

Mixed Up

As we hiked, further along, the suite of species gradually changed from oak to a mixed forest, to one dominated by conifers. With a much denser overstory of Douglas-fir, our path became almost completely shaded, and oak became non-existent. Instead, big leaf maple made up the deciduous canopy with many shade-loving (or at least shade-tolerant) plants in the understory. Sword fern and snowberry were two species I spotted. 

In general, conifer forests like the one we were hiking through are very common in Oregon and becoming more common in the Willamette Valley.  But that doesn’t mean they don’t have value. Mixed/conifer forests provide habitat for many species, such as black-tailed deer and Swainson’s thrush. Nate told me that even Grey Jay (a species I usually associate with higher-elevation conifer forests) will occupy the site in the winter.  

A Douglas-fir forest with big leaf maples and sword fern.

Everyone Likes Ducks

At one point, the dense trees opened up and a brightly lit clearing of grasses and willows came into view through the thicket. A wetland! Wetlands are areas that tend to retain moisture for a large part of the year.  These soggy bottomlands also provide critical habitat for many species, like wood ducks and beavers that frequent the area. Wetlands are also a target habitat for restoration and protection, as many have been drained for other uses. 

Though Nate works for USFWS, he spends most of his time working on restoration projects that are on private lands; many of which are wetland projects. “People like ducks,” said Nate, so they tend to be the focus of these projects. In fact, Finley was originally established to provide nesting habitat for waterfowl. In this case, the Dusky Canada Goose lost a great deal of habitat from land subsidence following an earthquake. Of course, now the refuge takes a multi-species approach to management, focusing on restoring habitat for many species. Coincidentally, even if a wetland is established in the name of duck, many more species will benefit, including humans. Wetlands provide tons of ecosystem services! Wetlands are amazing water regulators and filters, for example. 

Pure Gold

Then, at long last, we arrived! An upland prairie! One of Nate’s favorite habitats in the refuge. According to Nate, upland prairie habitat is really important to many species of concern in Oregon, like the Oregon Vesper Sparrow and the Streaked Horned Lark.  Plant species like Kincaid’s Lupine, Nelson’s Checkermallow, Bradshaw’s Lomatium, and Willamette Daisy, are also rare but can be seen here. Plus oak savanna habitat is typically the only place in Oregon’s Willamette Valley you are likely to find the state bird—the Western Meadowlark.  

Dominated by grasses, like Roemer’s Fescue, and herbaceous wildflowers, like Oregon sunshine, oak savanna is a colorful Smörgåsbord in early spring. The diversity of grasses and forbs in oak savanna habitat also attracts a diversity of insects, which in turn attracts a lot of birds. Essentially, the entire system is driven by the right mix of native prairie vegetation. 

The view looking out at the restored oak savanna.

Time and Money

However, when it comes to restoration, getting that right mix can be a huge undertaking. Nate explained that the open prairie we were looking at used to be a lot of douglas-fir trees and hardly any grasses.  It took a lot of work, time, and expense to bring it back to a near-native state. Cutting down trees, mowing, and burning, as well as replanting native species, are all part of the restoration process.  A process that doesn’t really have an end, as continued mowing, burning and plantings are often needed to maintain the habitat. For example, golden paintbrush, a plant that was once extirpated from the state, needs regular burning to be maintained. Also, as a hemiparasitic species, golden paintbrush benefits from associations with other native species, like Oregon sunshine. 

Visit this spot in spring to see golden paintbrush in bloom, along with a whole host of other wildflower species.

Is it enough?

As you can see, restoration work can get pretty complicated. Research into understanding what species do best, and in what conditions, is another important component of restoration work. However, there is also the question of just how much to restore. Do you want an oak savanna that is 90% native, or will 60% do? Nate talked about the challenges around this sort of decision-making. If you can get an ecosystem 60% restored for a lot less cost and effort, maybe that is enough to restore the ecological function of the prairie. And if that is the case, shouldn’t we stop there? He didn’t have an answer. Nor do I. But these are important considerations for any restoration and/or management plant. When do we let nature do its thing? 

Connect the Dots

Another perhaps even bigger challenge when you are trying to restore an ecosystem that is about 99% lost is connectivity.  Nate explained—Many species need large tracts of land and the ability to migrate between and through the landscape in order to obtain desirable population densities.  Population density is simply the number of individuals in a population that live in a given area. “Song birds really need it,” said Nate, “small places are great, but song birds need more.”  When there is a large enough tract of land that is not segmented, the densities of birds, like the Western Meadowlark, are substantially increased. 

The question is how do we create connectivity? We don’t want the “traditional corridor of trees,” said. Though there is no simple answer, Nate does hope to improve conditions where he can. As mentioned earlier, a lot of the restoration work Nate does is off the refuge property, often in locations adjacent to a refuge. Helping landowners establish habitat on their property can expand the land area that supports species. Then, as Nate described, others see what is happening and want to get involved “and things spiderweb out.” 

A Rare Sight

One of the rarest habitats on the refuge (and in Oregon) is the wet prairie. Due to their location, Occurring in lowlands, especially floodplains, many wet prairies have been converted to agricultural land. Wet prairies are also different from upland prairies as they retain water for a portion of the year making them ideal for plants that like to occasionally get their feet wet. Water-tolerant grasses, like tufted hair grass, sedges, and wildflowers dominate wet prairies.  Unfortunately, the wet prairie is also rare on the Mill Hill Loop—we didn’t see any. 

According to Nate, you have to go to the Prairie Overlook to see wet prairie habitat. Besides being wet prairie, the land adjacent to the overlook is designated a Research Natural Area, set aside for education and research. It is also really special because it is one of the few places in the Willamette Valley that was never tilled. 

Looking out at the wet prairie from the Prairie Overlook.

Important Matters

As we finished the loop and made our way back to park headquarters, I asked Nate why people should care about protecting and restoring wildlife habitat. For Nate, it is all about awe—only in these places can you see a rare blue butterfly or hear a woodpecker cackle, or watch ten thousand geese take flight off the marsh. Experiences like these can inspire people to care about and appreciate the ecosystems around them.

Awe and Inspiration

We were nearing the golden hour as Nate and I parted ways both to our respective homes. But before I left, I pulled over at the Prairie Overlook to take a peek at the wet prairie Nate had mentioned earlier. With my mood light and the sun setting low in the sky over an expansive golden landscape, I really did feel a sense of awe and appreciation. It is amazing what a little bit of nature (and science) can do for the human spirit.

Nate Richardson has worked as a wildlife biologist for the USFWS for 12 years restoring native habitat for the Partners for fish and wildlife program. He got his BS in wildlife science at Oregon State in  2004 focusing on avian conservation and management. In his free time, he enjoys hiking, climbing, fishing, and spending time with his 9-year-old son. 

Hike with a Forest Hydrologist

Views from the Table Rock Wilderness Trail

“All life depends on it.”

This was the response I got when I asked Jonas Parker, Bureau of Land Management hydrologist, why anyone should care about hydrology. A no brainer, right? Well, sort of—Jonas elaborated, “hydrology needs to be functional. It needs to be in balance with the ecosystem it flows through.” 

A System in Balance

We don’t just depend on water to live, but we depend on the regulatory processes that sustain a healthy water system. 

Consider the human body—we need to take in a certain amount of water to be healthy. Too little water and you risk dehydration. Too much water and you risk overwhelming your body tissues.  Our body systems help keep the body in balance, even when our choices may not. Overwhelm or abuse these systems and the consequence is death.

In the case of an ecosystem, like a forest, the same principles hold true. Too much or too little water can be devastating for an ecosystem. Natural processes and cycles help stabilize and regulate the hydrological cycle. Overwhelm or abuse these systems and we could be looking at ecological and societal collapse.

In either case, it is the system that needs looking after, not just the water flowing through it. 

Land Management 

As a district hydrologist for the BLM, Jonas’ job is to look after hydrological systems on our public lands. One of these lands is the Table Rock Wilderness area—which is where I met up with Jonas for our hike. 

Jonas begins his descent from the meadows near Rooster Rock.

The Hike

  • Trailhead: Table Rock Trailhead
  • Distance: 7+ miles
  • Elevation Gain: approx 2500 feet
  • Details: We hiked from the Table Rock Trailhead to Rooster Rock Trailhead. Roads to both trailheads are gravel but in decent condition. Road to Rooster Rock Trailhead is a bit rough; high clearance recommended. Ample parking available. Pit toilet available at the Table Rock Trailhead.

Views of a Patchwork Forests

Ironically, our wilderness hike started out on an old road that maybe 30 years ago was used to haul away timber. So, even though our intention was to experience wilderness, we found ourselves face-to-face with industrial timber production. 

The Table Rock Wilderness is a 6,028-acre swath of mostly hundred-year-old uncut forested land. It was established in the 1980s as part of an effort to protect what little remained of unharvested forests in western Oregon. However, the Table Rock wilderness is almost completely surrounded by industrial timberlands, both public and private. Therefore, when views opened up along the trail, we found ourselves looking down on a patchwork pattern of forest in various stages of production.

Beyond the Horizon

Looking beyond the horizon, the patchwork of Oregon’s forests become even more complicated. Almost half of Oregon is forested. About a ⅓ of is owned by private forest owners, while the remaining ⅔ are public forests, managed by government agencies like the BLM and USFS.  A majority of the timber harvest is done on private land, where economics is often the primary driving factor. While the remaining timber harvest on public lands works to meet multiple objectives. 

The BLM’s Northwest Oregon District alone manages about 800,000 acres of land, much of it secondary growth from clear-cuts in the mid-1900s.  A time period when timber production and economic gains was the priority. Now, our public lands are managed for multiple uses, including timber production, but with ecological and social considerations to balance.  To accomplish these goals which may seem to be in conflict with one another, much of the land that the BLM manages are held in reserve, including the Table Rock Wilderness.

In other words, much of Oregon’s forests are the product of out-of-date forest management practices that don’t necessarily jive with our current goals.

Views of a patchwork forest.

Modifying the Land 

Pretty quickly, Jonas and I made our way off the road and deep into the douglas-fir/western hemlock forest.  “Look at this chunk of land,” said Jonas, “diversity of species and canopy layers, appropriate spacing and correct vegetation. It doesn’t need anything.”  The hydrology of this forest is functional.  However, “most of the lands [in western Oregon] don’t look like this.” Most of our forest lands have been modified at one point or another.  And modification changes the hydrology. 

Jonas explained—”Whatever and however you modify the landscape there are going to be consequences.” For example, when a forest is clearcut, the amount of water that trees transport from the soil to the air, a process called transpiration, will decrease, as there are fewer trees to do the work. 

However, if that same area becomes overgrown with lots of shrubs, or is replanted at a high density with trees, transpiration will increase again.

Each of these modifications changes the amount of water in the system which may lead to problems.  For example, too much water added to the system when transpiration decreases may result in more runoff, higher stream flows, and erosion. Too little water and you may be looking at a dry streambed. 

“It’s this balance of modifying the landscape to accommodate different objectives,” said Jonas, which makes his work fun.

Looking toward the Table Rock Wilderness Area.

Quality and Quantity 

So when we are talking about changing the hydrology, what does that really mean?

I asked Jonas how he defined hydrology. He said, “The grade school answer is it is the study of water.” But, he added, hydrology can really be “broken down into two measurements—water quality and water quantity.”  If water quality and quantity are good, then you are looking at a healthy system.  However, in a modified forest, maintaining water quality and quantity can be a challenge. 

Clean, Clear Water

According to Jonas, when it comes to water quality in a modified forest ecosystem, there are two factors that should always be considered in order to ensure good water quality.  

The first is turbidity.  Turbidity is the cloudiness of the water.  In most forested ecosystems, the turbidity should be low most of the time—that is the natural state of a forest stream unless there is a rainstorm or snowmelt which naturally induces erosion and thereby increases turbidity. However, any human activity that disturbs the soil, like building roads or harvesting timber, can also mobilize sediment so that it may enter a body of water. This is a huge problem especially for aquatic organisms— it can clog fish gills and smother eggs; reduces stream visibility; and it can absorb heat. It can also make drinking water treatment more difficult.

Second is the water temperature. Most rivers in Oregon are inhabited by cold-water adapted species. However, with climate change, early snowpack melt, and the removal of forest from along rivers or streams, high water temperatures are becoming a more frequent problem. High temperatures are problematic because they can reduce the amount of dissolved oxygen a stream can hold.  Warm temperatures can also lead to the growth of algae. Algae can throw the ecosystem off balance by reducing oxygen concentration as they decompose, as well as producing cytotoxins. 

Keeping it Clean

However, Jonas explained, proper management can help mitigate turbidity and temperature problems. For example, maintaining a vegetative corridor along rivers and streams can provide shade that prevents water from heating up, as well as help filter out sediments. According to Jonas, the primary shade zone is about 85 ft—this is where 95% of shading occurs. These “riparian areas or buffers” are prescribed by the fish biologists and hydrologists and, in the case of BLM land, a 120 feet buffer is maintained on perennial streams where stream temperature is a concern just to be on the safe side.

In addition, to reduce the risk of damage from road construction, road use, and road work, waterbars can be placed along logging roads at regular intervals. These redirect water and sediments into the forest where it can settle out, rather than allowing it to flow directly to the stream. Jonas pointed out one of these waterbars on the road we walked in on.

A waterbar from our road walk.

Too much or Too Little of a Good thing

On the water quantity side of things, the discharge, or rate, of freshwater flowing through an area is important. Or in the case of a lake, the volume of water. And since most of the water Oregonians consume comes from forested land, modifications to forestland that changes the amount of discharge of a stream is not acceptable. 

Some of the mitigation measures used to reduce pollution can also help with efforts to protect water availability.  For example, directing water flowing in ditches toward the forest (as opposed to directly into the stream) can help slow its flow. A good riparian area can do the same thing. However, much of BLM land has been managed since the 1930s with a goal of intensive timber production, so they are stocked at levels that may be too dense for balanced water quantity. Remember too many trees can mean less water available to the system. 

Hard Decisions

As the focus of the BLM has shifted more towards a balance between resource protection and resource production in recent years, Jonas says, “The struggle is always there to balance the economic, the ecological, and the social.” Sometimes you have to make management decisions that aren’t popular, like thinning a riparian area, in order to reduce transpiration and bring the hydrology into balance.  And though it would be nice to leave things alone and let cycles restore on their own, it takes a lot of time.

“We also have threatened and endangered species—fish, owls, you name it—and their survival depends on a healthy functional riparian area. The question I would ask is, ‘Can they wait two to three hundred years?’”

A Spring! 

Early on in our hike, Jonas and I found ourselves startled by a rare find—a spring right in the middle of the trail!  Coldwater was bubbling right up from the ground! Jonas pointed out that the geology around us is responsible for the formation of a spring. 

A spring right in the middle of the trail.

Geology Brief

The Table Rock Wilderness has a volcanic geological history. The basement rock in the area is a volcanic rock called andesite, probably remnants of an old stratovolcano that existed 17-10 million years ago. Layered on top of the andesite, is a different type of volcanic rock called basalt. The basalt probably formed from lava that flowed into the area and cooled about 4 million years ago from a nearby Cascade volcanic eruption. 

At one point during the hike, you skirt around basalt pillars—called columnar basalt—that makeup Table Rock’s summit. One of the many cool geological sights on the hike.  

Columnar basalt on the base of Table Rock.

Hidden Water

All that being said, it is the volcanic nature of the Table Rock Wilderness that influences a part of hydrology that is often overlooked—groundwater.  About ⅓ of water on Earth does not flow on the surface but exists underground. In comparison, surface water—lakes, rivers, etc—makes up only about 1% of all freshwater. 

In the case of the Table Rock Wilderness, much of the water that lands in the forest will infiltrate into the ground and recharge “deep, deep basaltic aquifers”—huge groundwater storage zones.  

Because basalts tend to fracture, Basalt rock aquifers tend to be very permeable and porous making them ideal for supplying water to springs and seeps. 

“Springs regulate themselves and fluctuate very little,” said Jonas. The Table Rock Wilderness hydrological system is in balance in part because “water that enters the aquifer is equal to the water that leaves.” He went on, “Shallow aquifers are more prone to weather and drought. But that is not what we got here. Here we are 4,000 feet up on a basalt mountain!  If there is that much water coming out of the ground, that amount is going to fluctuate very little throughout the year.” 

Let it Snow

After a couple of miles of hiking in the woods, the trail opens up to views of Table Rock. It was here—while hiking through a rockfall that supposedly is inhabited with Pika—I saw a glimmer of white at the base of table rock. It was snow! 

Water in its many solid forms makes up about 2/3rds of freshwater on the planet—by far the biggest chunk. O.K. so most of that is probably accounted for in the polar regions. But still, glaciers and snowpack are incredibly important water reservoirs in the Pacific Northwest.  

According to Jonas, snow is still the largest reservoir of water in Oregon. And in the Table Rock Wilderness, this is also the case. Though most (well, basically all) of the snow had melted by the time we hit the trail, it was still working its way through the hydrological system underground, ultimately bubbling up to the surface through springs and seeps. 

Looking out to my right from the base of Table Rock, I could also see Mount Hood in the distance. Similar to how Table Rock supplies water to its creeks, Mt. Hood and the rest of the Cascades, supply water to some of Oregon’s largest rivers and most populous areas.  For example, the McKenzie River is a spring-fed system—supplied by a mountain snowpack that melted, infiltrated, and has been traveling underground for several years!   

Table rock sitting just above a rock fall. Can you spot the snow?

Wondering about Watersheds

After returning to the woods and circling Table Rock, Jonas and I eventually hit the switchbacks that take you to the top of the rock. Though Jonas opted to hang back, I had heard the views were too spectacular to miss, so I made the ascent alone.

It was worth it! Looking out across the landscape at the mountains, ridges, and valleys, was spectacular.  It also brought me back to discussion Jonas and I had earlier regarding watersheds. 

Anytime you are standing on the planet Earth, you are standing in a watershed. A watershed is simply an area of land that drains to a common body of water.  For the Table Rock Wilderness this common body of water is the Molalla River. 

A Drop at the Top

As Jonas described it—if you take a drop of water and place it on the top of Table Rock it will travel a number of different ways—it might travel to Image Creek to the north or Bull Creek to the south—but ultimately it will end up in the Molalla River. That is because the Table Rock Wilderness sits in the middle of the Molalla River Watershed. The Mollala River and Table Rock Wilderness are connected, even though the river never flows within the wilderness boundaries. This connection extends to the Willamette River as well. The Molalla River is the largest undammed tributary to the Willamette River.

So standing on the top of Table Rock, I was standing in the Mollala River Watershed, the Willamette River Watershed, and the Columbia River Watershed, as well as probably one or two smaller watersheds nested within. 

Though I didn’t spill any water at the top (other than sweat), it was still fun to trace the journey of a drop in my mind. A practice I recommend trying next time you are on a ridge.

One of many views from the top of Table Rock.

An Uncut Forest

After visiting the Table Rock summit, Jonas and I continued along the Saddle Trail and High Ridge Trail toward Rooster Rock. These trails led us back into the forest and through some gorgeous wildflower meadows. 

Taking in all the unique features of the area, Mine and Jonas’ conversion came back to a topic we touched on earlier—change. Change is part of the cycle of a healthy functioning ecosystem. In fact, the Table Rock Wilderness formed following a forest fire about 100 years ago.

View of a wildflower meadow looking up at Rooster Rock.

Things are Changing

But, Jonas asked, “What will it look like in 100 years? 200 years?”  With climate change creating hotter, dryer conditions, will we see a shift away from the Douglas-fir/ Hemlock forest to one filled with Pine and Madrone? As wildfires become more frequent and severe, how will that change the dynamics of the landscape? And, perhaps most importantly, should we step in?

Wilderness areas are for the most part “untouched,” but with global crises like climate change and biodiversity loss, we need to start considering our impact on these untouched places, and whether or not we should do anything in response. “We need to acknowledge no management is management,” said Jonas. 

Neither Jonas nor I had the answer, but we need to keep asking the question—How do we best protect our public lands?

Sweat Worthy

After several hours of sweating it out on the trail, Jonas and I followed the Rooster Rock Trail down to the trailhead where we had staged our return vehicle. 

Overall, the hike was long and challenging, but the scenery was worth every bead of sweat. I definitely recommend hiking the Table Rock Wilderness. Just make sure you pack enough water! 

Jonas Parker is a Hydrologist for the BLM Northwest Oregon District. He received his B.S. in Fisheries and Aquatic Science at Utah State University and Masters in Natural Resources Management from the University of Idaho. 

Hike with a Hydrologist

The Zigzag River flowing through the forest.

Flaming clouds of airborne gases, ash, and fine sediment rush down Mount Hood at 100 miles per hour, like an incinerator in flight. A slurry of hot water and sediment, in some cases 100 meters high, and the consistency of cement, follow—crashing down Mount Hood’s rivers and valleys; rocking and rolling between ridges; decimating everything.

This is Mount Hood 1,500 years ago. This is Mount Hood at various points during its geological history. Heck! As an active volcano, this is Mount Hood in the future.

Massive amounts of sediments were redistributed down the mountainside with each eruptive period. Sediments filled in valleys and creating an eerie lifeless landscape—in effect, a clean slate.

Mount Hood from Highway 26.

The Beginning

Which brings me to where our story begins…

I met up with hydrologist James (Dar) Crammond at the junction of Road 39 and Highway 26 to explore the Zigzag River Valleys.

Little Zigzag River and Big Zigzag River are fed by a glacier near the base of Mt. Hood’s crater, converging to become the Zigzag River further down the mountainside. They also sit precariously in the path of destruction described above.

However, despite this, Dar and I did not find ourselves hiking through a dry, flat moonscape, but a deep valley and forested oasis. The clean slate from 1,500 years ago was not clean anymore. It had been written upon by the very substance we had met up to talk about—water!

James “Dar” Crammond standing next to a logjam in the Zigzag River.

The Hike

  • Trailhead: Unmarked trailhead off of Road 39 at the gate for Forest Service Road 2639-021 where Paradise Park Trail Begins.
  • Distance: 2.5 miles
  • Details: Recreation Pass for US Forest Service Trails may be required. Limited parking and no parking at the trailhead. Little Zigzag Falls Trailhead is at the end of Road 39 and is a great add on to this hike.

A Giant Reset 

Before we hit the trail, Dar took me to an overlook of Mount Hood a little further east up 26 from our meeting point. As I stood there marveling at Mount Hood, Oregon’s tallest and most well-known stratovolcano, Dar explained Mt. Hood’s recent eruptive history. 

In addition to the eruptive event 1,500 years ago (the Timberline eruptive period), the Zigzag episode (500 years ago) and the “Old Maid” episode (200 years ago) also sent pyroclastic flows (airborne debris flows) and lahars (water and sediment flows) down Mount Hood. In fact, in 1804-05 Lewis and Clark observed the remnants of debris flows in rivers coming from the Mountain into the Columbia. Consequently, this is how the Sandy River got its name.

The Sequence

Dar also pointed to the horseshoe-shaped crater on Mount Hood with a tooth in the middle, called crater rock. He explained that each time an eruption would occur the dome would collapse leaving a crater, but then the dome would grow and the volcano would erupt again. Crater rock is a remnant of one of these collapsed domes. Hot spots around crater rock signify the potential for a new dome to build.

In addition, the heat energy from each eruption would liquefy all of the ice, snow, and glaciers on Mount Hood. The superheated water would flow down the mountain at high speed, collecting material along the way.  This “mudflow” is what is known as a lahar. Unlike pyroclastic flows, which are airborne, lahars flow down the mountainsides a bit slower, but much farther. This is why Lewis and Clark were able to observe debris from Mount Hood in the Columbia River many years ago. There is even evidence that the Columbia was temporarily dammed by lahar debris at least once following an eruptive episode. 

Dar called this whole sequence “a giant reset”— as it flattens the terrain with loose sandy material and rocks—setting the stage for a new force to come in and shape the landscape—water! 

Exposure at the end of Road 39.

Loose Landscapes

Leaving the viewpoint, Dar and I headed back to our meeting spot and drove up Road 39. At the end of the road is a parking lot and trailhead, as well a section of old Route 26 that was decommissioned in the 1960s. However, that is not why we stopped here. Instead, Dar wanted to show me an exposure that would provide some insight into the aftermath of Mt. Hood’s eruptions. 

The exposure was probably 25 to 30 meters high and made up of fine textured sand. Growing along the exposure were red alder trees. Dar said, “Alders love loose landscapes” When you see red alders in an area it suggests disturbance. 

Dar explained that during the 1550 eruption that a big lahar, with a peak 30% to 50% higher than what we could see, dropped down into the area where it would have been constrained as it moved down the canyon, causing it to ricochet from cliff to cliff.  Eventually, the slurry of water and sediment would meet a constriction point downstream where the Little and Big Zigzag meet– blocking sediment transport and causing loose sediment to pile up.  Hence, the alder trees.

Red Alders growing along exposure.

Sediment Stratigraphy 

This exposure was one of many Dar and I observed, as we moved downstream along road 39 to begin our hike through the woods.

Another exposure that was particularly interesting was near the pinch point where the Zigzag River tributaries meet and the canyon narrows (just above the trailhead on road 39). Here you could see horizons, or layers, of sediment from different eruptive events.

Dar explained how scientists can use organic bits found in the horizons, like a fragment of charred wood, to date each layer.

He also explained how sediment size and mixing within a horizon, is evidence for the origin of each layer.  Fine, consistently sized grains of sediments signal the normal hydrology of rain and snow. While jumbled sediments of variable size and shape are characteristic of lahar deposition.

Of course, even between different eruptive events, lahar depositional characteristics will differ depending on the stage of dome-building in which the eruption occurred. Fine material is more predominant in layers from early-stage eruptions, while large angular rocks are found in late-stage eruptions that follow dome-building.

Sediment stratigraphy near the confluence of Little Zigzag and Big Zigzag.

A Reckoning

Either way, we are talking about a lot of loose sediment! This is where hydrology comes into play, explained Dar. The powerful forces of big disasters often capture the imagination, but it is during the aftermath of these moments, where the real work begins. It is with the power of a raindrop and the force of a river that water reshapes the landscape—tearing down what plate tectonics builds up.  In this case, a forested canyon just waiting to be explored.

A Giant Sandbox

When I was a kid I loved playing in the sand at the beach—digging holes, building sandcastles, and watching the waves wash it all away. Now that I have my own children—I am fascinated by how many hours they can spend playing in the sand.

For hydrologists, this fascination doesn’t stop at childhood. Hydrologists “play in the sand” all the time. In fact, many hydrologists work with small-scale “sandbox” models.  Provided enough sediment and a continuous supply of water, these models help hydrologists better understand the large-scale ways water shapes the Earth.

The Zigzag River system is important to hydrologists because like a sandbox model, it too has a continuous supply of water and plenty of sediment—but it can be studied on a real-world scale.  As Dar put it—it is a “giant sandbox.”

Let’s go play! 

Hydrology Basics

Just a little past the confluence of Big Zigzag and Little Zigzag, Dar and I headed into the woods near the Paradise Park Trailhead.  Here we followed the Zigzag River downstream along a lovely forested trail.

Stream morphology is influenced by a lot of different factors which makes interpreting a river’s path challenging for hydrologists. Unless you can directly observe the river as it takes shape, you must rely a lot on inferences.

However, according to Dar, there are still some basic principles and observations that offer a good starting point for understanding river dynamics.

Gradient

The first of these being steepness. Steep rivers tend to be more straight—water energy is directed downward resulting in deep, narrow channels. Flat rivers tend to meander or curve—water energy is directed unevenly, cutting one bank, while slowing and dropping sediment on the opposite bank.

Streamflow

The second principle involves streamflow. Streamflow or discharge is a measure of the volume of water flowing through a channel at a given point and at a given moment. Dar explained to understand streamflow you want to consider its velocity, or speed, as well as the cross-sectional area of the river. Knowing streamflow is important because, it not only tells you how much water is available, but it correlates with the kinetic energy of the stream. High flows will have a greater amount of energy, than low flows.

Streamflow is also dynamic. Thus, depending on how much the discharge fluctuates during a day or a year, the energy of the flow and the morphology of a stream may depend heavily on the time of day and/or seasonality. Even within a channel, streamflow can vary as water tends to follow the path of least resistance- resulting in more complex stream channels, with features like meanders, pools, gravel bars, etc.

Play Pooh Sticks

So next time you pass by a river or stream, take some mental measurements of all of that water rushing by—is the terrain steep? How much water is there? Throw a couple of leaves or sticks in the water and see how long it takes them to get from point A to point B. A quick game of “Pooh Sticks” and you can consider yourself an honorary hydrologist. 

Riffle-riffle-riffle

Walking in the shade of the forest, we passed a turbulent section of the Zigzag River with impressive white water. While I was admiring it and snapping pictures, Dar explained what was going on.

“This is a riffle-riffle-riffle morphology,” he said. “It is fast because of the high gradient.” In a youthful stream, like the Zigzag River, water tends to follow the quickest path downhill. This generates a lot of erosive power and downcutting. Therefore, even though it was hard to see through all the white water, the loose sediment that makes up the Zigzag river bed was moving—transported downstream. 

In contrast, streams with different flow regimes or sediment supplies have very different morphologies. For instance, if we were looking at a stream with no sediment load or an older stream where the stream bed was eroded to bedrock, we would be looking at a “pool-drop-pool-drop” morphology. Or if we were looking at the Zigzag River when the eruptions smoothed everything out, a single channel would have yet to be established. Instead many small, braided channels would make up the landscape.

Riffle-riffle-riffle morphology on the Zigzag River.

Wood is a Wildcard 

As important as gradient, streamflow, and sediment supply are to the morphology of a river, there is another factor of often equal importance. Dar described it as “a wildcard” when it comes to morphology—and that is wood! 

As we continued following the trail downstream, we began to notice places where wood had fallen in the Zigzag River and altered its morphology.

Small Jam

One of the first examples we took note of was a small log jam. One end of a log had fallen into the stream and was still sticking out of the water on the other end—what Dar called a subhorizontal arrangement. 

“There are only four or five ways a tree can interact in the water,” explained Dar. It can stick straight up and down, stick out from the bank, create a perfect dam across, or be subhorizontal in the water.  Each of these creates different eddy patterns that accelerate the water in some places, scouring away sediments; while slowing down water in others, allowing sediments to accumulate creating bars or other depositional features. 

With our small log jam, it was easy to see this lopsided pattern of stream erosion and deposition—there was erosion on the bank nearest to us and deposition on the opposite bank. In fact, some of the small boulders on the depositional side had been sitting in place long enough for moss to grow. 

Small logjam on the Zigzag River.

Big Jam

As we walked further along the tree-lined trail, we saw more examples of how wood was altering the morphology of the Zigzag River, changing it from a narrow, straight channel to one with increasing complexity.  

Eventually, we ran into what Dar described as a “classic logjam.” The logjam was elaborate with two piers produced from tree fall on each bank. These piers slowed the water upstream, allowing for some pooling and deposition especially during high flows. In addition, the piers constricted the current—sending it through the middle of the river. The energy from the constriction was enough to scour the bottom of the stream, removing sediment, and creating a large scoop pool in the middle of the jam. 

Dar also explained how logjams—like the one in front of us—form and are naturally maintained. When trees growing along a bank are undercut, they will fall into the river where they will collect sediment. If enough sediment is collected, another tree may grow in the sediment and eventually fall.  So it is the repeated falling in of trees that creates and perpetuates logjams in a river. 

Big logjam on the Zigzag River.

Restoration in Reverse

Of course, one might wonder why logjams even matter. According to Dar, “wood is critical” in the Pacific Northwest. Wood naturally alters forested streams and has been doing do so long before humans arrived on the scene. Fish and other aquatic life have evolved in these wood enhanced streams. Thus, complex stream systems are essential for the survival of many of our culturally and ecologically important species, like salmon. 

Unfortunately, when Europeans arrived on the scene, rivers were seen as a resource for commerce and transport. So wood, which interfered with these goals, was cleared out.  Dar talked about how rivers like the Alsea and Nestucca were once wood-choked. However, with the removal of wood, they lost their complexity and their gravel. Now they are armored streams with hard rock and boulder bottoms. Dar called it, “restoration in reverse.” 

Now, we know better. And we have been trying to get wood back in the rivers to restore their lost functions. The Zigzag River serves as an important model for how a forested stream develops without human intervention; providing information for restoration work now and in the future.

Lost in Time

As the trail directed us away from the Zigzag River and back toward road 39, Dar’s and my conversation began to meander. I brought up a topic that seemed important to the Zigzag River story and hydrology in general—the concept of time. 

“Time is the 4th dimension of hydrology,” Dar said, “it is as big a parameter as anything else.” Even 100s of years of stream data and observation only provides a snapshot of the “life of a stream.”

In hydrology, change is relatively slow. It takes time for rocks to weather and erosion to occur; for banks to undercut and trees to fall; and for sediment to accumulate. Even faster processes like streamflow are restricted by time-bound processes like snowmelt and groundwater flow. Just like it is difficult to deduce the plot of a movie from one scene, our understanding of hydrology is time-bound and limited.

As Dar and I ended our hike on the Zigzag River, I reflected on all of this.

In only a few hours, Dar shared with me a fascinating story of a river—a story fashioned from a science that is only about 100 years old. Yet it is a story that has been playing for literally thousands of years and will play for thousands more. We are just getting started.

James “Dar” Crammond is the director of the USGS Water Science Center in Portland, Oregon. He also worked as the Chief of the Water Research Branch for USFWS and began his career with the Bureau of Reclamation in 1997, where he was a water rights expert. Dar has a B.S. in hydrology and J.D. from the University of Arizona, and is a member of the Arizona and Oregon State Bar Associations. 

Hike with a Geophysicist

Robert (Bob) Lillie at the summit of Marys Peak

Have you ever wanted to travel back in time to see what the Earth was like thousands or millions of years ago? Well, then this post is for you!

A hike on Marys Peak is like a window into Oregon’s geological past. Marys Peak’s rocks, viewpoints, and vegetation, all paint a picture of large-scale changes that occurred in Oregon millions of years ago, and continue to shape the landscape today.

Hiking with Robert (Bob) Lillie—a geophysicist with a knack for interpreting the Oregon landscape—is like having a tour guide along for the journey.

Armed with a simple model of Marys Peak, rock samples, and two books on Oregon Geology authored by Bob, he met me at the Day Use Area on Marys Peak to begin our hike.

View of Marys Peak from Beazell Memorial Forest’s south meadow.

The Hike

  • Trailhead: Summit Trailhead (Marys Peak Day Use Area)
  • Distance: 3.5+ miles (summit loop trail + meadowedge loop trail)
  • Elevation Gain: approx 700 feet
  • Notes: Northwest Forest Pass is required to park at the Marys Peak Day Use Area where you will find ample parking and pit toilets. There are many additional hiking options on Marys Peak of various length and difficulty.

Marys Peak Rocks

Holding up a labeled bicycle helmet as a model, Bob explained that Marys Peak was made up of several layers of different types of rock, each with unique properties. At the base was black volcanic rock called basalt, followed by thick layers of light colored sandstone and dark shale, and at the top an intrusive rock known as gabbro. This hard gabbro layer, Bob pointed out, is where we would be hiking today.

Bob’s bicycle helmet model of Marys Peak.

Cool Rocks

You may recall from middle school science, that igneous rocks form when lava or magma cools and solidifies.  However, due to differences in formation and chemistry, not all igneous rocks turn out the same. Bob pulled out some rock samples- gabbro and basalt- and began to explain their differences.

Dark-colored basalt is a low-silica igneous rock that forms from thin, fast-flowing lava (think Hawaiian volcanoes) that cools and hardens quickly— within a few hours to days. Gabbro is also dark-colored with the same low-silica chemical composition as basalt, but forms from magma that cools very slowly below ground, taking 10s to 1000s of years to cool and harden.

The long cooling time allows large crystals to form in gabbro rock. On the other hand, basalt has very fine crystals, making it a bit dull looking and less valuable. Thus, gabbro is used in masonry in Oregon, often as a granite alternative, while basalt is used to gravel roadways.

Image Credit: Lillie, Robert. “Oregon’s Island in the Sky: Geology Road Guide to Marys Peak.” Wells Creek Publishers, 2017.

Putting the rock samples away, Bob and I followed the gravel road part of the summit loop trail upward from the parking lot. Eventually, we reached some gabbro outcroppings, with large crystals glimmering in the sunshine. 

Heading up the summit trail to the first set of gabbro outcroppings

Weathering Time 

Remember, gabbro forms below ground. According to Bob, two miles of sedimentary layers once covered the now exposed gabbro rock. Of course, that was millions of years ago. So what happened? Where did the sedimentary layers go?

The answer lies in one of the most underappreciated geological processes— weathering an erosion. Weathering is the breakdown of rock by contact with the atmosphere, hydrosphere, and biosphere. Basically, exposed rocks get worn down over time with a little help from the environment.  This weathered material can then be eroded (moved away by wind and water), uncovering more rock that lies below. Sedimentary rock weathers and erodes easily, while igneous rock such as gabbro is much harder. 

 “Look up,” Bob exclaimed, “imagine two miles of sedimentary rock pushing down from above you.” 

The slow action of weathering and erosion removed it all! What a load off!

Mini-Yosemite 

As we hiked along the gabbro rock gardens, Bob pointed to some rounded outcroppings of gabbro rock that reminded me of pillow basalt— a form of basalt that results from cooling in water. Though pillow basalt can be viewed on the road up to Marys Peak, it made no sense that we would find it here in the gabbro layer. Something else was going on! Bob explained that the answer lies in a process known as spheroidal exfoliation.

With the slow removal of the weight of two miles of sedimentary rock layers, the gabbro sill would have fractured and broke into cubed or rectangular blocks. Then, spheroidal weathering would have taken over—discriminately breaking down the gabbro blocks; wearing down corners more than edges, and edges more than faces; and eventually forming rounded spheres surrounded by concentric “shells” flaking off.  Once exposed, these layers may erode and “peel” away layer by layer—much like peeling away the layers of an onion.

Spheroidal exfoliation on a gabbro outcropping

Bob compared the rounded rocks on Marys Peak to the huge granite domes (such as Half-Dome) you can see in Yosemite National Park. The same basic mechanisms of exfoliation apply, just on a different scale. Thus, Bob dubbed Marys Peak a “mini-Yosemite” in honor of the striking resemblance.

Hard as a Rock

At about 500 feet above the rest, Marys Peak is the highest mountain in Oregon’s Coast Range. In part, Marys Peak stands out above the other mountains because it is hard-headed or, as Bob puts it—stubborn! Compared to the sedimentary rocks that once covered it, the gabbro on top of Marys Peak is very resistant to weathering and erosion. The stubborn gabbro thus acts as a sort of shield to the elements, allowing the peak to remain prominent.

Image Credit: Lillie, Robert. “Oregon’s Island in the Sky: Geology Road Guide to Marys Peak.” Wells Creek Publishers, 2017.

Island in the Sky 

The fact that Marys Peak is “stubborn, has essentially allowed it to maintain its height and, in turn, a cold subalpine climate. Marys Peak, as Bob describes, is “an island in the sky.” 

With colder, harsher conditions than other coastal mountains, Marys Peak exists as a remnant of the past. Rather than the typical Coast Range Douglas-fir/hemlock forest, Marys Peak is a botanical anomaly, and a very beautiful one—it has even been designated a Scenic Botanical Special Interest Area.   

The meadows, rock gardens, and noble fir forests that make up the upper reaches of Marys Peak are unique to the Coast Range today, but once would have been typical of the region. Botanically speaking, Marys Peak is living in the last ice age that ended about 12,000 years ago. Many subalpine wildflower species are found here. During our hike through the rock garden, Bob and I took note of several: harsh Indian paintbrush, spreading phlox, Cascade desert parsley, and Cardwell’s penstemon, to name a few; and in the meadows- glacier lilies.  

A gabbro wildflower rock garden on Marys Peak

Marys Desert?!?

But subalpine flowers were not the only botanical anomaly of note on Marys Peak. As we hiked farther up the summit trail, past most of the rock gardens, Bob pointed out a slightly lower ridge to the left on the south flank of the mountain.  Here we found another remnant of the past—a veritable desert!  

Some 6,000 to 4,000 years ago, during a warm, dry period, species still found today in the eastern or southern parts of Oregon spread into parts of western Oregon.  Later, as the climate again shifted toward cooler and wetter, most of these—what are known as xeric species—retreated back.  But this outcropping- with it’s thin, rocky soil (thanks again to stubborn gabbro) and it’s harsh, drying winds- held onto its xeric species. The west-facing of this area is especially important because high winds coming from that direction blow away most of the heavy snow blanket that covers other areas near Marys Peak summit. 

I was unable to see or identify xeric species from where I stood, but prostate lupine (eastern Oregon species) and sulfur flowered buckwheat (southern Oregon species) are apparently two xeric species to keep an eye out for. 

Marys Desert—A xeric rock garden (desert ecosystem) on the west-facing slope of Marys Peak  

Story Beneath the Scenery

About ½ mile from the start of the trail, we reached the summit of Marys Peak. Ignoring the unsightly communication towers behind us, we looked out into the horizon. The views on Marys Peak are reason number two for visiting—come for the wildflowers, but make sure you stay for the viewpoints (and the geology)!  

From the summit, looking to the west, you can see the Pacific Ocean; and to the east the Cascade Volcanoes are prominently on display, with the Willamette Valley in the foreground. With such scenery, it is easy to get caught up in the simple beauty of Oregon.

It’s also the perfect opportunity to start thinking like a geophysicist—which, according to Bob, involves observing the landscape and visualizing what happened beneath Earth’s surface to cause it.  Much of geology happens slowly. We can’t watch changes occur, but we can use what we do see to develop inferences regarding the past. Like watching the final scene in a movie, it isn’t too difficult to deduce some of the earlier scenes if you are paying attention.  As Bob puts it- “there is a story beneath the scenery.”  

Views from the summit of Marys Peak

Moving Plates

The Earth is composed of about 12 hard tectonic plates that move around on a softer part of the mantle, called the asthenosphere. These plates grind past one another, and they grow and shrink as they move toward, under, and away from each other.  The motion is messy, resulting in cracking and folding, as well as earthquakes and even volcanic eruptions. These large-scale motions help explain much of Earth’s formations, including those visible from the top of Marys Peak. 

Born in the Ocean

Marys Peak did not start out as a peak. Rather, Marys Peak, and the Coast Range in general, started out as rocks and islands scattered about in the Pacific Ocean. What is now Oregon did not exist 200 million years ago! Over long periods of geological time, the North American plate bulldozed these rocks and islands off the ocean floor, and in the process built Oregon.  

As Bob explained, Oregon sits along a convergent plate boundary, where the North American and Juan de Fuca plates have been colliding for millions of years. More importantly, due to differences in density, the oceanic Juan de Fuca Plate has been diving beneath the continental North American Plate—a process known as subduction.  

But subduction is not a clean or smooth process.  Anything massive that doesn’t fit under North America is scraped off the oceanic plate and added to the continent. These masses of land, called exotic terranes, are responsible for a good portion of Oregon’s land mass, including Marys Peak and most of the coast range.  

In the case of Marys Peak, the basalt lava flows and overlying sedimentary rock layers formed in the ocean.  Later, as the oceanic plate subducted beneath the western edge of Oregon, magma intruded into these rock layers, forming vertical dikes and horizontal sills of gabbro (like the one that forms the “stubborn” caprock of Marys Peak). As the plate convergence continued, a large block of rock was thrust upward and eastward along the Corvallis Fault. Marys Peak was born!  

The other Coast Range mountains visible from Marys Peak summit are similarly composed of volcanic and sedimentary rocks from the ocean that were thrust upward and over the edge of the continent. And like Marys Peak, many of the other high Coast Range mountains are capped by hard, intrusive gabbro. 

Image Credit: Lillie, Robert. “Oregon’s Island in the Sky: Geology Road Guide to Marys Peak.” Wells Creek Publishers, 2017.

Volcanic Peaks

Marys Peak is not a volcano, but from Marys Peak you can see a great many volcanoes. From our vantage point, Bob and I were able to see Mt. Hood, Mt. Jefferson, and the Three Sisters; and, later in the day, Three Fingered Jack, Mt, Washington, Mt. Bachelor, and Diamond Peak. On clearer days you can also see Mt. Rainer, Mt. St. Helens, Mt. Adams farther north; and Mt. Thielsen, Mt. Mazama (Crater Lake), and Mt. McLoughlin to the south. Marys Peak offers views of most of Washington’s and Oregon’s great Cascade Volcanoes! 

I love the Cascade Volcanoes and can’t help but smile anytime I can see them off in the distance. But why are they there? Is there a story beneath the scenery? 

Don’t Sweat! 

Yep! Once again, plate tectonics provides an explanation.

When an oceanic plate subducts, as is occurring off the Oregon Coast today, it starts to sweat!  At about 50 miles below the surface the plate is under so much heat and pressure that it begins to metamorphose and dehydrate. The hot water released reacts chemically with overlying rock, causing it to melt and generate magma. The result is the starting material for repeated volcanic eruptions. 

For the last several million years, the Cascade Volcanoes have been fed by the magma generated by the subduction of the Juan de Fuca Plate below the North American Plate.  The volcanic peaks have erupted countless times during this time period, building up their cone shapes with each eruption.  Though it may seem infrequent on a human timescale, eruptive periods are frequent- with more than 100 Cascade eruptions over the past few thousand years.  As long as subduction continues, the Cascades will continue to erupt. 

Image Credit: Lillie, Robert. “Oregon’s Island in the Sky: Geology Road Guide to Marys Peak.” Wells Creek Publishers, 2017.

The Dynamic Duo: Uplift and Erosion

As Bob pointed out, while tectonic activity is building up volcanoes and lifting up mountains, the other half of a dynamic duo is tearing it all down. The effects of erosion can also be observed at the summit of Marys Peak. 

The Marys Peak region once had an additional two miles of sedimentary rock sitting on top of it!  As the land was lifted up, wind, rain and snow were, at the same time, wearing it down. Sedimentary rock is easily eroded, but Marys hard-headedness—aka her gabbro top—is a big reason she remains tall today. 

The effects of erosion can also be be observed in the Cascade Volcanoes.  When volcanoes become inactive and are no longer being built up by eruptions, they start loosing their tops.  Mt. Washington and Mt. Thielsen are great examples of this. Their pointy tops suggest they haven’t erupted in a really long time, as glaciers have etched away their smooth cones. Yes, even volcanoes show signs of aging!  One the other hand, Mt. Hood’s symmetrical cone shape is a good indicator of “recent” volcanic activity. 

Story of People

After spending several minutes at the top of Marys Peak discussing the “story beneath the scenery,” Bob and I continued our hike, moving downward along the summit trail until we reached the Meadowedge trail junction. Here we took a left and followed the Meadowedge trail. 

Toward the end of that loop, Bob stopped me, suggesting one more time we read the landscape. 

 “What do you see?” He said. 

I looked out across a rolling meadow. But with thoughts of plate tectonics running through my head, I overlooked what he wanted me to see. Finally, he pointed it out- a stage!  

Following WWII, a group known as the Shriners began holding an annual fundraising event on Marys Peak known as the Marys Peak Trek. Each year thousands of people attended to enjoy food and entertainment. One of the meadows even became a parking lot. The damage was extensive. But by 1983, the Trek ended, and the meadows have had some time to start to recover. Even the earthen stage is easy to miss if you aren’t looking for it.  

The Shriners Trek stage.

Bob and I ended our hike by completing the meadowedge loop back to the summit trail, where we hiked through Noble fir forest back to the parking lot where we said our goodbyes.  

Back to the Future

I am not ready to say goodbye to Marys Peak.

Marys Peak still faces many challenges. Rare meadows have been encroached on by Noble fir forest, at least in part due to human disturbance. Social trails and wildflower gathering remain a constant threat to the meadows. And then there is climate change, threatening the very existence of this ice-aged ecosystem.

However, there are also many forces working to preserve Marys Peak. Meadows are being restored and Noble fir populations kept in check. Signs and barriers mark sensitive areas. And many local community groups, like the Marys Peak Alliance, are working to educate visitors on the ecological and cultural importance of Marys Peak.

As we look forward to the future of Marys Peak, it is my hope that it remains as it is today: a future set in the past.

Dr. Robert J. (Bob) Lillie is a free-lance writer, science communicator, and interpretive trainer. Bob was a Professor of Geosciences at Oregon State University from 1984 to 2011. He studied geology at the University of Louisiana- Lafayette and Oregon State University while earning his bachelors and masters degrees, and later studied geophysics at Cornell University where he earned his Ph.D. 

Bob has written extensively about Pacific Northwest geology in “Beauty from the Beast: Plate Tectonics and the Landscapes of the Pacific Northwest” and “Oregon’s Island in the Sky: Geology Road Guide to Marys Peak.” Both books are available at area bookstores, museums and visitor centers, as well as on amazon.com

Run Around the Alvord Desert: Let’s Playa

The Alvord Desert Playa

With the walls closing in at home, my family and I decided to head out to the Alvord Desert for some much needed solitude and wide-open space for a weekend in mid-May. The plan was to camp for a couple nights, and hike and explore during the day. The Alvord Desert is on BLM land and primitive camping is allowed. So, with the promise of room to roam, we packed up our vehicle with the necessary provisions, loaded up the car, and headed southeast. 

Alive in the Alvord

The Alvord Desert is a playa located on the east side of Steens Mountain- a huge fault block mountain that runs for miles at the edge of Oregon’s Basin and Range region. Dry and expansive (about 11 miles long and 6 miles wide), with a cracked earthen floor. The Alvord Desert landscape feels alien- devoid of greenery and seemingly lifeless; a monotonous swath of dirt and dust. Much like what you would expect from a desert.

But then…

You watch the sun rise and fall, casting shadows and painting the sky intermittently between hours of moon and stars and wind. You roam the sagebrush boundary lands, hunting for lizards or other desert life. When the sun is high and the heat is too much, you swat away invertebrates while reading the book you brought on the trip, moving every once in a while in order to remain in the shade. On your early morning run, you discover large pools of water that make you reflect on what you know about hydrology (more on that later). And suddenly, you find yourself waxing poetic about this mysterious landscape called the Alvord Desert… Or maybe it is just me.

Arrival 

After driving for countless miles, my family and I arrived in Alvord Desert late in the afternoon. It was finally cooling down for the night, when we found a spot to camp on the edge of the playa. There, we spent the evening watching our shadows grow long and once night hit, we counted stars and waited for the moon to rise. Eventually, one-by-one, we fell asleep to the sound of the desert winds, visions of wide-open-spaces dancing in our heads.

The Hike or Run 

  • Trailhead: any place you can find your way back to (make sure you know your return coordinates)
  • Distance: any distance your energy level will allow
  • Elevation Gain: virtually none
  • Notes: Run or hike from virtually any point you would like. Bring plenty of water. Distances appear shorter in the desert, so plan accordingly. Make sure you know where you are starting from, so you can make it back safely.
Heading out on a sunrise run.

A Glass Half Full 

At first light, I was up and ready to explore. My plan from the get-go was to run the playa: so much space and nearly level ground- a distance runners dream, I thought. So I donned my running gear and started to move. The light of the early morning was magic, as I trotted along at my usual slow pace, soaking in the atmosphere. I followed the shrub-lined edge of the playa for most of the run. It was eerie and peaceful.

Eventually, I made it around to the opposite side from camp and figured I would cut across the playa when- splash- water! What I had thought was a desert mirage, was actually a thin lake of water that made crossing the playa at that point impossible.

Rerouting my run, questions began to soar through my mind about the wet encounter. I had read that the Alvord desert had a wet and dry season, but for some reason it didn’t fully register until that moment; until I ran smack into it.

Tired and a bit dehydrated from my run, I thought a lot about the hydrological cycle of the Alvord- about its cycles and seasons- and decided I needed to know more about this unique land of wet mud and dry dust.

Ready? Let’s Playa in the Alvord!

The Alvord Desert covered with a thin layer of water

In the Shadow

Lying within the rain shadow of Steens, the Alvord Desert is considered the driest place in the State of Oregon, receiving only about 7 inches of precipitation per year. As part of Oregon’s interior, not a lot of moisture makes it to this southeastern region. And what little does makes it into the region, is removed from the atmosphere as snowfall on Steens Mountain’s western flank. This process is known as the rain shadow effect. When moisture laden air travels up a mountainside (the windward side), it cools, condenses, and eventually falls as precipitation. The dry air then continues down the other side of the mountain (the leeward side), where it heats up, encouraging further drying through evaporation.  The Alvord Desert is on the leeward side of Steens, so it not only gets little rainfall, but it experiences a lot of evaporation.

Dry and Cracked 

Additionally, the Alvord basin, like most watershed in the Basin and Range of Oregon, is a closed-watershed system. Instead of taking a more traditional route to the Ocean, water in the Alvord doesn’t leave by surface or groundwater flowing to the Ocean. Instead, it stays in the basin until the hot sun evaporates it away. The result is another interesting features of the Alvord- cracks.

Alvord Desert’s surface is riddled with geometric shapes separated by cracks. Known as desiccation fractures, these cracks form as the surface of moist clay-rich sediments dry and shrink through sun and wind evaporation. Shrinking results in tensile stresses that radiate out in all directions on the surface that ultimately break, resulting in polygonal cracks- one of the Alvord Desert’s characteristic features.

Desiccation Fractures

Reflecting on a Thin Film of Water

O.K. so that explains why it is so very dry in the Alvord Desert, but it doesn’t explain why there is water there at all.  Where does the water come from, if not from precipitation?

Perhaps not surprisingly, much of the water in the Alvord Desert comes from higher up- on Steens Mountain.  Steens Mountain captures a lot of precipitation in the form of snow. Later in spring, the snowpack melts and feeds streams and groundwater systems that supply water to the basin below. Much like how water accumulates in the drain at the bottom of your sink, the Alvord Desert is one of several low points, separated by alluvial divides, that capture water draining from Steens above. 

Steens Mountain

Shifting Waters

However, as a desert playa, the Alvord Desert also happens to be very large and very flat. In the spring, expansive areas fill with water but at a depth of only a few centimeters. It is the process of inundation that actually helps maintain the flatness of a playa- laying down sediments evenly throughout.

When visiting the Alvord Desert it is important to remember that these thin, but massive lakes of water may grow or shrink, and/or shift, making parts of the playa potentially impassable at times. During my morning run on the playa, it was just a matter of rerouting, but there is potential for getting stranded by these shifting waters. In the Spring, when water levels are wide, the risk of getting trapped by pooling water is particular high, so plan accordingly.

An Ancient Lake

However, even during its wettest season, the thin surface water of the Alvord is nothing compared to the amount of water it once held during its tumultuous past. From about 3.5 million years ago to 15,000 years ago, recurring ice ages increased rainfall in southeast Oregon that filled the large basins characteristic of the region. The Alvord Desert and surrounding sub-basins (as far south as Nevada) were all connected as one massive pluvial lake. Filled to the brim, Pleistocene Lake Alvord had a depth of nearly 200 feet at one point, and would often overflow. 

Overflowing

During periods of overflow, water would travel via Crooked Creek to the Owyhee River.  During one cataclysmic event, water burst through Big Sand Gap on the lake’s eastern rim, eroding it down about 12 m, and sending torrents of water into the much smaller Pluvial Lake Coyote, through Crooked Creek, and out to the Owyhee River. Today along Crooked Creek, you can observe the scabland terrain and boulder bars that serve as evidence of this event.  Apparently, you can also hike out to Big Sand Gap from the Alvord Desert by following wild horse trails to see the breach up close- something I will have to try on my next trip.  

It wasn’t until the last 10,000 years that the Earth warmed again and the Alvord became the desert you see today. 

Alvord Desert at sunrise

You Should Go Playa

Whether you explore on foot or otherwise, the Alvord Desert is a magical place to visit. It may look one-dimensional at first glance, but if you stay awhile, the dynamic nature of the landscape, with it’s subtle shifts and movement, begin to unfold. You should seriously go “playa” in the Alvord- you won’t be disappointing. Just don’t forget the moisturizer.

  • “Alvord Desert – The Oregon Encyclopedia.” 20 Mar. 2018, https://oregonencyclopedia.org/articles/alvord_desert/. Accessed 26 May. 2020.
  • “Playa | geology | Britannica.” https://www.britannica.com/science/playa. Accessed 26 May. 2020.
  • Tanner P.W.G. (1978) Desiccation structures (mud cracks, etc.). In: Middleton G.V., Church M.J., Coniglio M., Hardie L.A., Longstaffe F.J. (eds) Encyclopedia of Sediments and Sedimentary Rocks. Encyclopedia of Earth Sciences Series. Springer, Dordrecht.
  • O’Connor, Jim E., Rebecca J. Dorsey, and Ian Madin, eds. Volcanoes to vineyards: geologic field trips through the dynamic landscape of the Pacific Northwest. Vol. 15. Geological Society of America, 2009.
  • “Oregon: A Geologic History – Oregon Geologic Timeline.” https://www.oregongeology.org/pubs/ims/ims-028/timeline.htm. Accessed 26 May. 2020.