It rises in southern Meagher County in the Castle Mountains and flows northwest in the valley between the Big Belt and Little Belt mountains, past White Sulphur Springs and past Smith River State Park.

[3] Noted for its spectacular scenery and blue-ribbon trout fishery, the Smith River is unique in that it has only one public put-in and one public take-out for the entire 59-mile (95 km) segment of river.

Boat camps located along the remote river canyon help preserve the unique quality of this area.

Permits for private floats on the Smith River are allocated to the public via a lottery system prior to the spring season.

[4] Areas near the Smith River are currently under review as nearby Meagher County and state agencies investigate construction of the Black Butte Copper Project.