1. Clark Fork River
At 310 miles long, the Clark Fork River, which we share with Idaho, is the largest river by volume in the state. It is named after William Clark, the explorer.
2. Missouri River
The longest river in America starts in Montana, flowing 2,341 miles before entering the Mississippi River in St. Louis, Missouri.
3. Roe River
In contrast, Montana also has the shortest River in Montana. The Roe River runs between Giant Springs and the Missouri River in Great Falls.
4. Yellowstone River
The Yellowstone River is a tributary of the Missouri River. It also happens to be the longest undammed river in the lower 48 states. It courses 692 miles through Wyoming, Montana, and North Dakota.
5. Bitterroot River
The Bitterroot River flows through some scenery so perfect, it will turn anyone into a Montana lover. The Sapphire Mountains rise to the east, while the Bitterroot Mountains are on the west side.
6. Milk River
The Milk River has a rather unique path. It’s formed in Glacier County, where the main stream flows east-northeast into Southern Alberta. From there it flows past the town of Milk River and turns southeast back into Montana. Then it passes through the Fresno Dam, east past Havre, then north and southeast, joining the Missouri River in Valley County.
7. Judith River
This Central Montana river was called Buluhpa’ashe, “Plum River.” Meriweather Lewis named it the Bighorn, but in 1805, William Clark named it in honor of his future wife, Julia (Judith) Hancock.
8. Flathead River
Ideal for fly fishing and part of some of the most beautiful scenery in the state, the Flathead River originates in the Canadian Rockies to the north of Glacier National Park before flowing southwest into Flathead Lake. After a journey of 158 miles, it empties into the Clark Fork.
9. Blackfoot River
The Blackfoot River is recovering from a case of poisoning caused by mining. But it’s doing well and is a great place for trout fishing. The Blackfoot was made famous by the novella (and the movie) "A River Runs Through It".