CHS 2 Hike - Coyote Wall—The Labyrinth Loop

4. Hot-Spot Volcanism – Flood Basalts

“POV: Party people have rented your basement apartment and it's a 17-million-year lease.”

Unlike the towering stratovolcanoes of the Cascades, another type of volcanism shaped vast portions of Washington: flood basalt eruptions. These immense lava flows originated from the Yellowstone Hotspot, a deep mantle plume over 300 miles to the southwest. As heat from the plume thinned and weakened the crust, deep fissures opened in what is now southeastern Washington, eastern Oregon, and western Idaho. Magma exploited these fractures, rising through miles of crust before erupting in a fiery river of destruction, covering vast areas and forming the Columbia River Basalt Province. Our hike will take us through one of the best-preserved basalt layers, revealing their immense scale and unique formations.

May Hike: Coyote Wall Trail - 6.3 (+2) miles, 1765 ft gain

Coyote Wall provides an up-close look at the massive flood basalts that flowed across Washington millions of years ago. The columnar basalt formations and exposed lava flows visible along the trail showcase the immense scale of these eruptions. The steep cliffs and rolling terrain here also highlight how subsequent erosion, faulting, and Ice Age floods have reshaped the basalt layers over time.

Additional information on other geology themed hikes can be viewed here: CHS 2025 Hiking through Deep Time - https://tinyurl.com/mr2su9jb

TBD