6. Scabland Coulee The floods left behind "coulees"—dry streambeds or gullies—all over what is now eastern Washington. Here, an old homestead sits in the bottom of a coulee within the ...

These events are known as the Missoula Floods or the Scabland Floods. The most recent epoch of flooding lasted from ~20 to ~15 ka BP, and occurred when the Cordilleran Ice Sheet (CIS) was near its ...