The Blackfoot River, sometimes called the Big Blackfoot River to distinguish it from the Little Blackfoot River, begins in western Montana 10 miles northeast of the town of Lincoln, then flows westwardly entering the Clark Fork River 5 miles east of the city of Missoula at the town of Milltown. The Blackfoot is renowned for its fly fishing and was the principle fishing location for the book and movie A River Runs Through It. The Blackfoot is a fast, cold river with many deep spots, making it prime habitat for several varieties of trout, and is excellent for canoeing and rafting with rapids in places of the category 3.

The highway paralleling Blackfoot River through a canyon from the town of Potomac until it empties into the Clark Fork and is subject to hazardous icing conditions in the winter, particularly black ice.

Rivers of Montana