How did the failure of the Lake Missoula ice dam shape the Channeled Scabland in Washington state?

Between approximately 17,000 and 12,000 years ago, ice tongues from the Cordilleran Ice Sheet periodically dammed the Clark Fork River in Montana, creating Lake Missoula. When this ice dam failed, it released a massive volume of water—estimated at up to 2,500 cubic km—that surged westward and southward across the Columbia Plateau in eastern Washington state.12

These catastrophic floods, known as jökulhlaups, dramatically reshaped the landscape of the Channeled Scabland. The torrents stripped away the existing loess cover and carved deep into the underlying basalt bedrock. This process created a distinct system of large dry channels, waterfalls, potholes, and longitudinal grooves. Additionally, the receding floodwaters deposited massive, coarse gravel bars and formed giant current ripples, which remain as prominent geological features of the region today.12