I thought it’s because there is nothing there that anyone wants. I always thought Wisconsin was paying them to keep it. I can think of entire US states I’d be willing to pay France to take over.

Yooper here. Your example is on the money, but perhaps moreso than you know: The UP is also heavily populated by Finnish-Americans, which helps explain the cultural resilience and independence as well. The same dimensions that have kept Finland independent from Russia, keep the UP independent from others - and, holy wah, if I had a nickel every time we talked about breaking away from the trolls South of the bridge while at deer camp...