The Tensas River is a river in Louisiana in the United States. The river begins in East Carroll parish in the north-east corner of the state and runs roughly south-west for 400km more or less in parallel with the Ouachita River. The two rivers merge in Jonesville, Catahoula parish to become the Black River. For the 20 miles south of Interstate 20 between Delhi and Tallulah, the river winds its way through the Tensas River National Wildlife Refuge. Waters abound with valuable gamefish such as channel catfish, largemouth bass, and black crappie.