A Wall of Ice…

And the World's Largest Recorded Freshwater Floods

Imagine the greatest floods on earth crashing across and sculpting the lands of the northwestern United States. The animation focuses on the Missoula Floods, a series of cataclysmic ice-age floods that occurred near the end of the last Ice Age. As ice dams repeatedly formed and failed in what is now western Montana, floodwaters surged across Idaho, Washington, and Oregon, carving canyons, transporting house-sized boulders, and leaving behind the distinctive landforms that define much of the region.

This was made possible through the support of the Federal Lands Recreation Enhancement Program and visitors to the National Park Service.