The river, known as Tensas Bayou in its upper reaches,[3] begins in East Carroll Parish in the northeast corner of the state and runs roughly southwest for 177 miles (285 km)[4] more or less in parallel with the Mississippi River.

The confluence of the Tensas and the Ouachita rivers, in Jonesville in Catahoula Parish, creates the Black River, not to be confused with Black Lake in Natchitoches Parish in north-central Louisiana.

In 1881 the Congress authorized the U.S. Army Corps of Engineers to improve the navigation by removing ordinary obstacles.

[5] The navigation work began at Dallas, a village on the stream in Madison Parish.

The bottomland hardwood forest near the Tensas River is some of the remaining habitat of the Louisiana black bear.