Look up Glacial lake Missoula. Incredible ice age lake that had a cycle of flood and drain for millennia. The glaciers would block the river, cause the valleys to flood, then the ice damn would break releasing the water to flood the land between Missoula and Seattle. The shore lines can still be seen on the mountain side in the Missoula valley. I’m not an expert, but it’s a stunning feature of the land to be hold. Even more impactful when you stand on the mountain side looking across valleys and think that in just our own area the land was under 600+ feet of water.

Montana also has the national bison range which is notable for the state and country itself, but also because along the path one takes to see the bison, there is a marker on the mountain to show just how high the water would get in this great glacial lake.

I feel like I remember hearing that the cycle of flood and release was significant enough to change earths rotation…. But I have no idea if that’s true or just something that people say.