It is geographical center of North America which includes Canada. We took US2 all the way to Washington state back in 1969 not in RV. Plan to retrace route this year with TT.
I only buy propane from rv park if no other choice. Most charge flat fee per tank size and even if by gallon higher than elsewhere. I have discovered Tractor Supply almost always at least 1.00 cheaper. Don't know how much of the country they cover.
Don't usually call it this but have sign "WELCOME TO OUR WHEEL ESTATE" used to have an international travelall son said it was like riding a Sherman tank so the name Sherman stuck