Over 40,000 cubic miles of basaltic lava, known as the Columbia River Flood Basalts, covers parts of Washington, Oregon, and Idaho.
These tremendous lava flows erupted between 17 and 6 million years ago. Over 300 high-volume individual lava flows have been identified, along with countless smaller flows.
The slightly depressed lava plain is now known as the Columbia Plateau.
Plan your vacation to the Pacific Northwest with 
