Explore the Scablands

Clark Fork River
Imagine a glacier filling this valley so that only a few mountaintops poked above the ice. The glacier, a southern tongue of the great Cordilleran ice sheet that covered western Canada in the last ice age, dammed up the Clark Fork River, creating Glacial Lake Missoula. When the ice dam (which stood in the far right of this image) burst under the lake's enormous pressure, up to 500 cubic miles of water barreled down this valley in just 48 hours.