The Marias River
|Basin countries||Chouteau, Hill, Liberty, Toole, Pondera and Glacier County, Montana|
|Mouth elevation||2,559 feet (780 m)|
|River system||Missouri River|
The Marias River is a tributary of the Missouri River, approximately 210 mi (338 km) long, in the U.S. state of Montana. It is formed in the Blackfeet Indian Reservation in Glacier County, in northwestern Montana, by the confluence of the Cut Bank Creek and the Two Medicine River. It flows east, through Lake Elwell, formed by the Tiber Dam, then southeast, receiving the Teton River at Loma, 2 mi. (3.2 km) above its confluence with the Missouri.
The river was explored in 1805 by the Lewis and Clark Expedition. Some of the men on the expedition mistook it for the main branch of the Missouri until their subsequent discovery of the Great Falls of the Missouri near Great Falls, Montana. The river was named by Meriwether Lewis after his cousin, Maria Wood.
The Marias is a Class I river from Tiber Dam to its confluence with the Missouri River for public access for recreational purposes.
- Montana Watershed Coordination Council