The Swan River in the western part of the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Montana

Montana

Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

 starts in the Mission Mountains

Mission Mountains

The Mission Mountains or Mission Range are a range of the Rocky Mountains located in northwestern Montana in the United States. They lie chiefly in Lake County and Missoula County and are south and east of Flathead Lake and west of the Swan Range...

 at Gray Wolf Lake and continues north to Swan Lake

Swan Lake (Montana)

Swan Lake is a lake located east of Flathead Lake and the town of Bigfork, Montana. The Swan River comes from the south and fills the lake. The lake is similar to Moyie Lake in southern British Columbia. It is a narrow, small, and twisty lake that is hard to navigate. There is a small divide...

. Then it goes west and is impounded by a dam before emptying into Bigfork Bay and the town of Bigfork

Bigfork, Montana

Bigfork is a census-designated place in Flathead County, Montana, United States. The population was 1,421 at the 2000 census.-Geography:Bigfork is located at ....

, where it enters Flathead Lake

Flathead Lake

Flathead Lake is the largest natural freshwater lake in the western part of the contiguous United States. With a surface area of between and , it is slightly larger than Lake Tahoe. The lake is a remnant of the ancient inland sea, Lake Missoula of the era of the last interglacial. Flathead Lake...

. The last stretch of the river is sometimes called the Bigfork River. It is a moderately sized river, draining the Swan Valley between the Mission Range and Swan Range

Swan Range

The Swan Range is a mountain range in western Montana in the United States . Its peaks typically rise to around . The range is bounded by the South Fork Flathead River to the east, the Flathead River to the north and northwest, the Swan River to the west, and lie to the southwest of Glacier...

.