Growing up in Central Oregon, I always saw the mountains.
They were there when I learned how to ride a bike, when I went to prom, when I experienced life and death in their shadows. Yet I don’t know a lot about these peaks other than touching the rocks on outdoor excursions and saying good morning to them while driving to work.
On a quest to learn more, I reached out to a variety of people to ask about the geology, ecosystems, and human connection with the Central Oregon horizon.
Creation
The first stop on my journey is to an office housing gorgeous rocks and pinecones and field trip equipment, including a box of overflowing hard hats. It’s the office of Hal DeShow, a Central Oregon Community College geology instructor who almost ran off the road the first time he saw the snow-covered Central Oregon Cascade Range near Madras seven years ago.
“My first epiphany with geology is that every square inch of landscape has a story,” DeShow said. “You can learn how to read that story if you can understand the rocks and the landforms.”
The story of the landforms on the Central Oregon horizon began with subduction approximately 40 million years ago (although the current peaks are much younger) when dinosaurs were long gone and the Earth was entering a time of great cooling.
About 100 kilometers down, the Juan de Fuca tectonic plate slid under the North American plate. The interaction of water rushing into Earth’s deep hot rocks lowered the melting temperature through a chemical reaction, creating magma. Magma is buoyant and rises into chambers that sometimes erupt when there are fissures in the Earth’s crust, building cones and peaks.
These regional volcanoes are part of the larger Cascade Range, spanning from northern California to central British Columbia, which in turn is part of the Ring of Fire circling the Pacific Ocean.
Central Oregon is unique because there is a second source of volcanism. The Pacific Northwest is being tectonically rotated clockwise, which causes Central Oregon to be slowly pulled apart in a process known as extension. The extension reduces the pressure on the underlying rocks, allowing them to melt into magma and erupt as volcanoes. There are 466 volcanoes from Mt. Jefferson to Crater Lake, according to DeShow.
Life
Life as humans know it in Central Oregon would not exist without the Cascade Range. The volcanoes cause precipitation and snowmelt that absorb through porous volcanic basalt rock to reemerge in springs that feed local rivers.
Springs offer a consistent water source, compared to flooding that is common in rain-fed rivers west of the Oregon Cascades, and contribute to high-quality water (as well as high-quality beer, I might add).
High-quality water helps the ecosystems, of which there are many in the varying elevations. Passes in the Central Oregon Cascades may receive 200-plus inches of precipitation, while 60 miles down the road it’s just 12 inches, according to Matthew Shinderman, senior instructor of natural resources at Oregon State University-Cascades. That can also influence food webs and ecosystems.
“Things are connected in obvious and not-so-obvious ways,” Shinderman said. “What happens in a portion of the landscape is not isolated. Interconnection is a good lesson we can learn, from this landscape in particular.”
Markers of different ecosystems are readily visible, such as changes in dominant tree species when moving up in altitude. Driving on Cascade Lakes Scenic Byway, one may notice the main tree species change from ponderosa pine to lodgepole pine to mountain hemlock as elevation rises.
Diversity acts as a strong component for resilience, Shinderman added. Diversity in biology, genetics and even human knowledge or skills can help to make a community resilient through change.
Since Broken Top and North Sister are older mountains on the horizon (Broken Top was active about 300,000-150,000 years ago and North Sister was active about 120,000-45,000 years ago), erosion has rendered their outlines more craggy and rugged compared to younger volcanoes such as South Sister and Mt. Bachelor, with smoother cones.
“Central Oregon looking west, everything is really young,” said Bart Wills, geologist with the U.S. Forest Service. “Geologically we are talking thousands of years old, and usually in geology we are speaking millions of years old.”
Using dating techniques, such as paleomagnetism and carbon dating, geologists have identified Mt. Bachelor’s oldest volcanic activity about 18,000 years ago. The most recent Central Oregon lava flow is the Newberry caldera Big Obsidian Flow, formed 1,300 years ago.
Interbeing
Since this landscape is so young, it’s possible that human beings have been witness to the creation that we see today. There is evidence that humans have been in Oregon for at least 15,000 years. Human relationships intertwined with volcanic change could have been challenging, according to DeShow. Pyroclastic flows threatened lives. But on the positive side, they also formed the valuable obsidian used in trade networks by Indigenous peoples.
GeorGene Nelson, an enrolled tribal member and director of the language department of the Klamath Tribes, which includes Klamath, Modoc and Northern Paiute people, said that the roads such as Highway 97 and 58 used to be trails for traveling back and forth for trade.
In the Klamath and Modoc languages, the Cascade Range is known as Yámakisham Yína, translated to “mountains of the Northerners.” Nelson said that the Klamath people have stories that only the strongest people who worked as doctors could go to some places in the mountains.
“They said spirits lived in the mountains and they would get strength or visions or abilities from the spirits in the mountains. They would be able to heal people and help people,” Nelson said. “For tribal people everything has a spirit — the rocks, the water, the wind, the fire — and so we’re taught to respect all of these things and to take care as we are considered caretakers. We have sacred spots in these mountains and so we go there to pray and to be at one with the earth.”
Many humans feel a spiritual connection when being by or in the mountains, including DeShow, who notes we should be thankful that the mountains exist and how our lifestyle and civilization here are completely dependent on the volcanoes. Trail networks, outdoor technology and roads have made it possible for humans to be present with the mountains in any season.
So what has learning about the Central Oregon mountains taught me?
Story. Resilience. Change. Spirit. And for me, love.
Now the question is, what do we do in return?
This article appears in Source Weekly November 28, 2024.
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