State lines really do a poor job of dividing regions nicely, like you've indicated. My home state of Ohio, for example, is a good demonstration of a border stat

State lines really do a poor job of dividing regions nicely, like you've indicated. My home state of Ohio, for example, is a good demonstration of a border state. Southeast Ohio is definitely transitional-Appalachia, whereas Northwest Ohio is all flatland cornfields where you'd struggle to differentiate from Iowa. I think your distinction is Upper Midwest vs. the legacy Northwest Territory/"Great Lakes" states. Midwest to outsiders seems to be a catch-all for "not West, not South, but west of the Appalachians" when in reality it's a mix of Great Lakes, Great Plains, and other gradients of other regions.