Montana Public Radio

Glacial Lake Missoula

Sep 20, 2013

"Fieldnotes," September 22nd & 23rd, 2013: "Glacial Lake Missoula," by Caroline Kurtz & Bruce Weide.

"Geologists estimate that Glacial Lake Missoula took about 60 years to fill the first time, and when the waters got deep enough to break up the dam and explode westward, the entire lake drained in less than 48 hours. As this titanic flood raced towards the Pacific at 45 to 60 miles per hour, it shaped the topography of 16,000 square miles of the Pacific Northwest, scouring out the channeled scablands and coulees of Eastern Washington. As the torrents swept through the area, they created many of the familiar landscape features we know and depend on today, such as the Missoula and Spokane aquifers, the fertile Willamette Valley, and numerous wetlands."

Map of Glacial Lake Missoula's floods.
Credit Wikimedia Commons