Beyond the obvious proximity to the five Great Lakes, what makes a region? The Midwest has its own stereotypes – the Rust Belt has become a popular term for northern post-industrial cities – but perhaps the draw of the Earth’s bounty of freshwater is more meaningful?
Aside from the cultural influence of the lakes, the Great Lakes region is a combination of environmental science, politics and economy.
Great Lakes Now
https://www.greatlakesnow.org/2021/09/map-region-definitions-great-lakes/