The Grand Canyon took 6 million years to carve. But the Channeled Scablands in Washington State were created in a single weekend. For decades, geologists couldn't explain these scars. Rivers don't move like this. Wind doesn't carve like this. The culprit wasn't a river. It was a bomb. 15,000 years ago, an ice dam holding back a massive glacial lake shattered. A wall of water 2,000 feet high tore across the Pacific Northwest, moving more water than all the rivers on Earth combined. We mapped the