Apgar's first post office was established in 1913, closing in 1930. It reopened between 1942-1944. Jesse Apgar was the first postmaster and the town was named for her family. Dimon Apgar and others cut a road from Belton through heavy forests to Lake McDonald and homesteaded there.
Apgar is located in northwestern Montana, it is two miles from the West Glacier Entrance to Glacier National Park.