Pacific Northwest Volcanic Activity Map.
Pacific Northwest Volcanic Activity Map.
Cascade Subduction Zone Diagram.
Volcano Types Diagram.
Basalt layer along the rim of Dry River canyon.
Columbia River Basalt exposed at Crooked River Gorge as seeen from Peter Skene Ogden Viewpont.
Columbia River Basalt on the Oregon Coast at Rocky Creek Scenic Wayside.
.Columbia River Basalt, Saddle Mountain, Oregon.
Basalt Rim along the White River, White River Falls State Park, Oregon.
Mount St. Helens from Johnston Ridge Hike.
Steam rising from Mount St. Helen's caldera.
Columbia River Basalt at Yaquina Head, Oregon.
Basalt outcroppings long Gnarl Ridge, Mount Hood, Oregon.
The Narrows swimming hole, Clackamas River, Oregon.
Basalt rim along the Deschutes River in Sawyer Park.
Basalt lava field at Lava Butte in central Oregon.
Lava River Cave, Newberry National Volcanic Monument.
Big Obsidian Flow, Newberry Volcano, Oregon.
Big Obsidian Flow, Newberry Volcano, Oregon.
Three Sisters from Broken Top, a heavily eroded and extinct stratavolcano.