The marker for the middle of the USA is on private
land
20 miles north of the
TheTriStateMuseum.com
which built a granite stone, but is not really the center.
The owner of the private land does not want tourists walking on his property,
and it is not for sale.
President Eisenhower added Alaska and Hawaii to the USA
Alaskans and Hawaiians are Americans
Belle Fourche, South Dakota: Center of the Nation Monument
https://www.roadsideamerica.com/tip/15142