This shit is off the hook.
I went to a lecture on the Ice Age floods at Dry Falls State Park. There's a massive hole in the ground that was carved away as ice dams melted and released walls of water across eastern Washington. Here's what I understand of its history: The area is composed of basalt layers from a long history of lava flows and re-directions of the Columbia River. Over time, the basalt stretched, creating cracks that were further compromised by 350' of rapidly flowing water. There's no archaeological evidence of human inhabitation, but if anyone was there it would have been a bad time. Stones pulled from the ground were carried as far as the Pacific Ocean.
My geologist grandfather describes the geology of Washington state as "notoriously complicated." It's largely formed by a patchwork of volcanic islands and bits of ocean floor. It's relatively young and unfortunately under-taught. Burke Museum: Northwest Origins has one of the better narratives available.
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