The Saint Mary River is a cross-border

tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage ...

of the

Oldman River The Oldman River is a river in southern Alberta, Canada. It flows roughly west to east from the Rocky Mountains, through the communities of Fort Macleod, Lethbridge, and on to Grassy Lake, where it joins the Bow River to form the South Saskatche ...

, itself a tributary of the

South Saskatchewan River The South Saskatchewan River is a major river in Canada that flows through the provinces of Alberta and Saskatchewan. For the first half of the 20th century, the South Saskatchewan would completely freeze over during winter, creating spectacular ...

. The Saint Mary together with the

Belly River Belly River is a river in northwest Montana, United States and southern Alberta, Canada. It is a tributary of the Oldman River, itself a tributary of the South Saskatchewan River. The name of the river may come from the Blackfoot word of , meanin ...

and

Waterton River Waterton Lake is a mountain lake in southern Alberta, Canada and northern Montana, United States. The lake is composed of two bodies of water, connected by a shallow channel known locally as the Bosporus. The two parts are referred to as Middle Wat ...

drains a small portion of

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

, in the United States, to the

Hudson Bay Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...

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 Saint Mary Lake is the second-largest lake in Glacier National Park, in the U.S. state of Montana. Located on the east side of the park, Going-to-the-Sun Road parallels the lake along its north shore. At an elevation of , Saint Mary Lake's wate ...

, exits the park and flows on into Lower St. Mary Lake in the

Blackfeet Indian Reservation The Blackfeet Nation ( bla, Aamsskáápipikani, script=Latn, ), officially named the Blackfeet Tribe of the Blackfeet Indian Reservation of Montana, is a federally recognized tribe of Siksikaitsitapi people with an Indian reservation in Monta ...

. From the reservation, the St. Mary River flows into

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

and into the

St. Mary Reservoir St. Mary Reservoir is a reservoir in southwestern Alberta, Canada. It was created for irrigation purposes by the damming of the St. Mary River (Alberta-Montana), St. Mary River, which was completed in 1951. The Kainai Nation's Blood Indian Reserve ...

. It flows into the Oldman River which eventually reaches the Saskatchewan River. It passes near the town of

Cardston, Alberta Cardston is a town in Alberta, Canada. It was first settled in 1887 by members of the Church of Jesus Christ of Latter-day Saints (LDS Church) who travelled from Utah, via the Macleod-Benton Trail, to present-day Alberta in one of the century' ...

, and the city of

Lethbridge Lethbridge ( ) is a city in the province of Alberta, Canada. With a population of 101,482 in its 2019 Alberta municipal censuses, 2019 municipal census, Lethbridge became the fourth Alberta city to surpass 100,000 people. The nearby Canadian ...

, Alberta.

Irrigation

The St. Mary River also provides water for irrigation in Southern Alberta. The St. Mary River Irrigation District (SMRID) is Canada’s largest

irrigation district In the United States an irrigation district is a cooperative, self-governing public corporation set up as a subdivision of the State government, with definite geographic boundaries, organized, and having taxing power to obtain and distribute water f ...

delivering water through of canals and pipelines to approximately of land south of the Oldman and South Saskatchewan Rivers between Lethbridge and

Medicine Hat Medicine Hat is a city in Southern Alberta, southeast Alberta, Canada. It is located along the South Saskatchewan River. It is approximately east of Lethbridge and southeast of Calgary. This city and the adjacent Town of Redcliff, Alberta, ...

. The irrigation project was started in 1898, and on September 4, 1900, the first water was brought to

by the project. In December 1945 the

Canadian Pacific Railway The Canadian Pacific Railway (french: Chemin de fer Canadien Pacifique) , also known simply as CPR or Canadian Pacific and formerly as CP Rail (1968–1996), is a Canadian Class I railway incorporated in 1881. The railway is owned by Canadi ...

transferred control of the projects to the government of Alberta, creating the St. Mary and Milk River Development (SMRD). A dam was created in 1946 on the St. Mary River, to service the irrigation system, and water finally reached Medicine Hat in 1954 upon the completion of the St. Mary Main Canal.

Notes

{{DEFAULTSORT:St. Mary River (Alberta-Montana) Landforms of Glacier National Park (U.S.) International rivers of North America Irrigation districts Irrigation in Canada Rivers of Glacier County, Montana Rivers of Alberta Rivers of Montana Lewis Range South Saskatchewan River Tributaries of Hudson Bay

Irrigation

See also

Notes