Channeled Scabland

The Channeled Scabland is a geological feature in eastern Washington, North America, formed by cataclysmic glacial floods. These immense floods, originating from the failure of an ice dam holding back glacial Lake Missoula between 17,000 and 12,000 years ago, surged across the Columbia Plateau.12

The floodwaters, with discharges up to 2 x 10⁷ cubic meters per second, overwhelmed preglacial river valleys. As they eroded loess and basalt, they carved out a vast network of scoured channels, creating the Channeled Scabland. This process is an example of stream overfitness, characterized by dramatic landforms like great cataracts. The evidence for these massive floods was documented by geologist J. Harlen Bretz, who faced initial opposition but ultimately convinced the scientific community of his findings.12