List of Longest Rivers in The United States By State - Montana

Montana

1. Missouri River – 2,340 miles (3,770 km)
2. Milk River – 729 miles (1,173 km)
3. Yellowstone River – 692 miles (1,114 km)
4. Kootenai River – 485 miles (781 km)
5. Bighorn River – 461 miles (742 km)
6. Powder River – 375 miles (604 km)
7. Clark Fork – 310 miles (500 km)
8. Musselshell River – 292 miles (470 km)
9. Tongue River – 265 miles (426 km)
10. Frenchman River – 212 miles (341 km)

See also List of rivers of Montana.