The Missoula Floods were a series of catastrophic floods that occurred around 15,000 to 13,000 years ago during the last Ice Age. These floods were caused by the periodic failure of an ice dam that held back glacial meltwater in the area of present-day Montana. When the dam broke, massive amounts of water surged across the landscape, carving out features such as the Columbia River Gorge and the Scablands of eastern Washington. The floods released an estimated 500 cubic miles of water, creating a dramatic transformation of the terrain. The immense force of the water shaped valleys and left behind sediment deposits that can still be seen today. The Missoula Floods are significant in understanding the geological history of the region and the impact of glacial activity on the Earth's surface.