Maphead - Very Large Pacific Northwest Body of Water

[iautah]

I read with interest about the Bay of the West on Jean Janvier's 1782 map of North America. Earlier this year, I read [u]Oregon's Greatest Natural Disasters[/u]. In that book, William L. Sullivan describes Lake Missoula, a huge Ice Age era lake in present day Montana (and a small part of Idaho). The lake was 600 feet deep. Periodically, the ice dams holding back the lake would break, causing massive floods of two hundred cubic miles of water racing at 80 miles per hour into the Columbia River Basin and the Willamette Valley - destroying everything in its path.