The Flathead River represents the combined flow of hundreds of headwater creeks funneled from the glacial cirques of Glacier National Park and other wild places within the U.S. and Canada. This cold, clear water flows into the North, South and Middle forks of the Flathead, which merge together near Columbia Falls to begin a southward journey. Portions of the upper mainstem Flathead River are classified as 'Recreational' within the Wild and Scenic River Classification system.

About 20 miles into its journey, after flowing down the gentle, south-sloping gradient of the Flathead Basin floor, the river empties into Flathead Lake. The lower mainstem Flathead River drains from the southwest corner of the lake and draws waters from an arid valley basin throughout its 75-mile course. The Flathead River finally empties into the Clark Fork River at Paradise.
 

The Flathead River System offers hundreds of miles of pristine waterways, while Flathead Lake is a scenic and recreational mecca. A diversity of fish and wildlife complement the land and water resources, and contribute to both the natural and cultural values of the Flathead Basin environment.