Columbia River Basalt Group

The Columbia River Basalt Group is a large formation of volcanic basalt rocks that formed during a series of massive eruptions around 17 to 6 million years ago. These eruptions released vast amounts of molten lava, creating extensive plateaus and layered basalt flows across parts of Washington, Oregon, and Idaho. This volcanic activity shaped much of the Pacific Northwest landscape, forming features like the Columbia River Gorge. The basalts are significant because they record a period of intense volcanic activity and have important geological, ecological, and archaeological implications for the region.