St. Mary is an unincorporated community on the western border of the Blackfeet Indian Reservation adjacent to Glacier National Park in Glacier County, Montana, United States. The village is the eastern terminus of the Going to the-Sun Road which bisects the park east to west, a distance of 53miles 85Square kilometre. Fewer than 50people reside in the village year round however, the population increases tenfold on a busy summer evening.
Several lodges, restaurants and cafes, a small grocery store, two gas stations and campgrounds are located in the village. A large housing area for National Park Service personnel is located adjacent to the village, but within the park. U.S. Route 89 passes through the village, which lies between Saint Mary Lake in Glacier National Park and Lower St. Mary Lake on the Blackfeet Indian Reservation.