Have you seen the magnificent, scoured rocks and cliffs that make the Columbia River Gorge in the Pacific Northwest? Or tasted the wines from the Willamette Valley wines in Oregon? Scientists say we can thank the massive floods from Glacial Lake Missoula in Western Montana for those landscapes and fine wines.
Glacial Lake Missoula and its catastrophic floods during the last ice age – roughly 12,000-18,000 years ago – are responsible for the amazing landscapes from Western Montana through Eastern Washington and the Columbia River Gorge out to the Pacific Ocean. Scientists believe Glacial Lake Missoula was formed by ice dams that held back what is now the Clark Fork River just before the Idaho border. These dams were 2,000 feet in depth and held back 600 cubic miles of water (as much as Lake Erie and Lake Ontario combined). When released, the flood waters’ force was equal to that of 60 Amazon Rivers. There is evidence that roughly 40 catastrophic floods originated from Glacial Lake Missoula, and giant current ripples can be seen in the hills throughout the region. Ice tore away soil, creating the scablands of Eastern Washington, and deposited mineral-rich sediment into the Willamette Valley.

Scientists say we can thank the massive floods from Glacial Lake Missoula in Western Montana for much of the landscape in the Western United States. Photo courtesy of Western Montana’s Glacier Country
For more information on Western Montana’s Glacier Country, visit GlacierMT.com.