If you know where to hike in Missoula, Montana, you’ll occasionally find yourself standing over several markers which indicate the high-water level of what was one Glacial Lake Missoula. Standing on top of Missoula’s peaks, it’s hard to imagine that once upon a time you would be standing on an island and everything you see below used to be underwater, but it’s true. Glacial Lake Missoula was a prehistoric lake at existed periodically
at the end of the last ice age and held approximately half the volume of Lake Michigan.
Where am I going with this, you ask? On numerous occasions throughout the years, the ice dam responsible for creating the lake failed. The resulting floods - known most commonly as the Missoula Floods, are responsible for much of the Columbia River Gorge we see today. Historians and scientists estimate that over the course of 2,000 years, cataclysmic floods swept over Idaho, Washington and Oregon at least 40 times.
I found it particularly fascinating to hear about the floods. I had previously known that Glacial Lake Missoula once existed but (call me crazy), I had always assumed it disappeared through a much more normal means: evaporation.
As we sailed up the Columbia River, our guides would point to narrow canyons and jagged rock formations and remind us that such features were formed by a rush and wall of water so great that rock was quite literally carved away. Though the sight would have been terrible to behold (not that you would have beheld it for long), the ending result is truly GORGE-ous (yes, I went there).