Jefferson River

The Jefferson River is a tributary of the Missouri River, approximately 83 miles long, in the U.S. state of Montana. The Jefferson River and the Madison River form the official beginning of the Missouri at Missouri Headwaters State Park near Three Forks. It is joined 0.6 miles downstream by the Gallatin.
  • Country: United States
  • State: Montana
  • Mouth: Missouri River
  • Length: 83 mi (134 km)
  • Basin size: 9,532 sq mi (24,690 km²)
Data from: en.wikipedia.org