Missoula flood



The Missoula flood was a massive catastrophic flood that destroyed much of the Pacific Northwest USA. It oc­curred at the peak of the Ice Age, following the global flood of Noah, when a glacial lake in the valleys of western Montana, broke through its ice dam and rushed through eastern Washington and down the current path of the Colum­bia River. It is believed the flood waters traveled at rates up to 35 m/sec carrying a discharge near 15 times the combined flow of all the rivers of the world.

Glacial Lake Missoula
Glacial Lake Missoula was formed when a finger of the Cordilleran ice sheet crept southward into the Idaho panhandle, forming a large ice dam that blocked the mouth of the Clark Fork River, creating a massive lake 2,000 feet deep and containing more than 500 cubic miles of water. Glacial Lake Missoula stretched eastward for some 200 miles and contained more water than Lake Erie and Lake Ontario combined. When the highest of these ice dams failed, lake water burst through, shooting out at a rate 10 times the combined flow of all the rivers of the world. This towering mass of water and ice literally shook the ground as it thundered toward the Pacific Ocean, stripping away hundreds of feet of soil and cutting deep canyons—"coulees"—into the underlying bedrock. With flood speeds approaching 65 miles per hour, the lake would have drained in as little as 48 hours.