Bretz Floods

Bretz Floods. Cataclysms on the Columbia. Poets, painters, and travelers have been inspired by the rugged beauty of the Columbia River Gorge - beauty that was shaped in large part by a single series of cataclysmic events that ended just 12,000 years ago. , As the massive Cordilleran Ice Sheet advanced from Canada during the last Ice Age, it damed rivers in Montana with up to 2,000 feet of glacial ice, creating huge lakes. The larger of these, 3,000-square-mile Glacial Lake Missoula, held over 500 cubic miles of water - half the volume of Lake Michigan. , When rising water broke the ice dams, tremendous floods burst across the land and down the Columbia River. Then the ice dammed the rivers and the lakes rose again. This lead to repeated torrents of water and ice raging down the Columbia Gorge - as many as 100 deluges over approximately 3500 years. The flood waters hammered at the mountains, causing vast landslides, scouring away soil at elevations up to 1,000 feet, and creating the spectacular escarpment and bluffs that inspire us today. , It's hard to imagine the sheer magnitude and force of the water that blasted through the Gorge during the Ice Floods. In the area around Stevenson, the roaring torrent crested up to 600 feet at speeds of up to 50 miles per hour in some places. The water tore savagely at the land, uprooting trees, leveling hill, and sweeping away wildlife.