I saw some documentary on something like this once. It was absolutely fascinating. There were big floods in Idaho too. There have really been some big catastrophies in the past, that's for sure.
Most early civilisations were based along the world's great rivers, or by the sea. We shouldn't be surprised that most such civilisations had folk-tales of terrible floods that killed nearly everyone. Just ask the citizens of New Orleans. Curiously (to those of a biblical literalist bent) dry-and-high ancient civilisations don't share those myths.
The question that I've been wondering about is, what flood inspired the flood stories that we find in the world's major religions? A flood in Idaho is very interesting, but it would have been the tree that fell in the forest that no one heard. What flood's echo is found in the Book of Genesis? Was it a particular flood? If so, there was apparently a major flood about 7,500 years ago when the Mediterranean broke through the Straits of Bosphorous into the Black Sea. That's the one the settlements were found in, not the Mediterranean, BTW (my mistake, sorry).
These created the Channeled Scablands of eastern Washington. Did some field trips through there in grad school. Very interesting features. But too early for the biblical flood, though, and not nearly global enough.