Ouachita River
![](/Images/godic/202501/31/Ouachita_River,_Arkansas1025.jpg")
![](/Images/godic/202501/31/Ouachita_watershed1026.png")
![Blakely Mountain Dam on the Ouachita River in Garland County, Arkansas. The dam impounds the Ouachita Reservoir.](/Images/godic/202501/31/USACE_Blakely_Mountain_Dam1026.jpg")
![Columbia Lock and Dam on the Ouachita River](/Images/godic/202501/31/USACE_Columbia_Lock_Ouachita_River1026.jpg")
The Ouachita River (/ˈwɑːʃᵻtɑː/ WAH-shi-tah) is a 605-mile-long (974 km) river that runs south and east through the U.S. states of Arkansas and Louisiana, joining the Tensas River to form the Black River near Jonesville, Louisiana. It is the 25th longest river in the United States (by main stem).