cus at first blush, it seems like a really sensible suggestion and i myself cannot think of any fault with it in principle
Transcript:
We should base our regions off watersheds instead of state lines, for example, this is the midwest [diagram of the Great Lakes–Saint Lawrence River Basin]
https://amtrak-official.tumblr.com/post/736885520460906497/we-should-base-our-regions-off-watersheds-instead
It'll work at least as well as drawing lines arbitrarily