Dissecting the Cascade Range: Geology of the Columbia River Gorge

The Columbia River does something few rivers in the world do. It cuts through the active volcanic arc of the Cascade Range, which is both being pushed up by tectonic forces and being built up by hundreds of young volcanoes. The Gorge gives us a detailed cross-section of the inner workings of the Cascades, from volcanoes to soils, in a part of the Northwest where both of those things change! The Oregon and Washington sides are similar, but shockingly different over both the length and width of the Gorge. Geologists have learned a lot in the past 100 years, but every answer to a question seems to bring up more questions than it answers.