The Blue River is a 141-mile-long (227 km)[1] tributary of the Red River in southern Oklahoma in the United States. Via the Red River, it is part of the watershed of the Mississippi River.
According to the Geographic Names Information System, the river has also been known as Blue Creek. The Board on Geographic Names settled on "Blue River" as the stream's official name in 1977.
The Blue River originates in southeastern Murray County, 2 miles (3 km) southwest of Roff. It flows east into Pontotoc County and turns southeast through Johnston and Bryan counties, past the town of Milburn and within 3 miles (4.8 km) of Durant. It joins the Red River in southeastern Bryan County.
The Blue River is unique to Oklahoma in that it is one of the last free flowing streams in the state; water flows freely from its source to the ocean without dams or other man-made structures controlling the flow of water. Native fish are bass and catfish. Trout are brought to the river at the Blue River Fishing Area northeast of Tishomingo, making it a designated Oklahoma trout stream from November 1 till March 31. This brings anglers to fish for rainbow and brown trout during the colder months when the rivers waters are at its coldest.