@xkcd some of those areas overlap. like, the ice age floods in eastern Washington did a lot to uncover the interesting "flood" basalts (called because they aren't associated with a volcano, but seem to have bubbled up from fissures and covered wide flat areas, totally different than the ice-dam floods)

Also, the Willamette valley in Oregon is where the floodwaters ended up, and ultimately they're a result of glaciers blocking up water in montana, so like, yeah, multiple things at play.

@xkcd

Yeah, "geological" covers almost everything.

Is it unknown what caused upstate New York?

@xkcd

"Ongoing Disputes Between Limestone And Water" - I now have a Tom&Jerry-like cartoon in my head.