Black River (Louisiana)

Ouachita River
River
Ouachita River in Ouachita County, AR
Country	United States
States	Arkansas, Louisiana
Tributaries
- left	Little Missouri, Saline, Tensas
- right	Caddo, Little
Cities	Hot Springs, AR, Camden, AR, Monroe, LA, West Monroe, LA
Source
- location	Ouachita Mountains, Polk County, Arkansas
- coordinates	34°41′56″N 94°19′57″W / 34.69889°N 94.33250°W / 34.69889; -94.33250
Mouth	Black River
- location	Catahoula Parish, near Jonesville, Louisiana
- coordinates	31°37′53″N 91°48′25″W / 31.63139°N 91.80694°W / 31.63139; -91.80694Coordinates: 31°37′53″N 91°48′25″W / 31.63139°N 91.80694°W / 31.63139; -91.80694
Length	605 mi (974 km)
Map of the Ouachita River watershed. The Ouachita joins the Tensas River near Jonesville, Louisiana to form the Black River (Louisiana).

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).

The Ouachita River begins in the Ouachita Mountains near Mena, Arkansas. It flows east into Lake Ouachita, a reservoir created by Blakely Mountain Dam. The North Fork and South Fork of the Ouachita flow into Lake Ouachita to join the main stream. Portions of the river in this region flow through the Ouachita National Forest. From the lake, the Ouachita flows south into Lake Hamilton, a reservoir created by Carpenter Dam, named after Flavius Josephus Carpenter. The city of Hot Springs lies on the north side of Lake Hamilton. Another reservoir, Lake Catherine, impounds the Ouachita just below Lake Hamilton. Below Lake Catherine, the river flows free through most of the rest of Arkansas.