St. Mary River (Alberta–Montana)
| Saint Mary River | |
|---|---|
St. Mary River downstream from Saint Mary Lake | |
Location of the mouth in Alberta | |
| Location | |
| Countries | United States and Canada |
| State | Montana |
| Province | Alberta |
| Physical characteristics | |
| Source | near Gunsight Lake |
| • location | Glacier National Park, Lewis Range, Glacier County, Montana, United States |
| • coordinates | 48°37′13″N 113°44′37″W / 48.62028°N 113.74361°W |
| • elevation | 7,560 ft (2,300 m) |
| Mouth | Oldman River |
• location | near Cottonwood Park, Alberta, Canada |
• coordinates | 49°37′38″N 112°53′13″W / 49.62722°N 112.88694°W |
• elevation | 2,739 ft (835 m) |
The Saint Mary River (Blackfoot: Apahktóksipisskan), is a cross-border tributary of the Oldman River, itself a tributary of the South Saskatchewan River. The Saint Mary together with the Belly River and Waterton River drains a small portion of Montana, in the United States, to the Hudson Bay watershed in Canada.
The river rises as a stream on Gunsight Mountain in Glacier National Park and flows into Gunsight Lake, then flows into Saint Mary Lake, exits the park and flows on into Lower St. Mary Lake in the Blackfeet Indian Reservation. From the reservation, the St. Mary River flows into Alberta and into the St. Mary Reservoir. It flows into the Oldman River which eventually reaches the Saskatchewan River.
It passes near the town of Cardston, Alberta, and the city of Lethbridge, Alberta.