The Red River rises near the edge of the northwestern dip slope of the Llano Estacado mesa in two forks in northern Texas and southwestern Oklahoma. The North Fork Red River meets the southern and largest fork near the Texas–Oklahoma border. The southern fork, which is about 120 miles (190 km) long, is generally called the Prairie Dog Town Fork. It is formed in Randall County, Texas, near the county seat of Canyon, by the confluence of intermittent Palo Duro Creek and Tierra Blanca Creek.
Crossing the Red River at the Texas–Oklahoma border from I-35
The Red River turns and flows southeast through Palo Duro Canyon in Palo Duro Canyon State Park at an elevation of 3,440 feet (1,050 m), then past Newlin, Texas, to meet the Oklahoma state line. Past that point, it is generally considered the main stem of the Red River. Near Elmer, Oklahoma, the North Fork finally joins, and the river proceeds to follow a winding course east through one of the most arid parts of the Great Plains, receiving the Wichita River as it passes the city of Wichita Falls. Near Denison, the river exits the eastern end of Lake Texoma, a reservoir formed by the Denison Dam. The lake is also fed by the Washita River from the north.
Point bars, abandoned meander loops, oxbow lakes
in Lafayette and Miller counties, Arkansas
After the river flows out of the southeastern end of the lake, it runs generally east towards Arkansas and receives Muddy Boggy Creek before turning southward near Texarkana.
Soon after, the river crosses south into Louisiana. The sister cities of Shreveport and Bossier City were developed on either bank of the river, as were the downriver cities of Alexandria and Pineville. Where it is joined by the Ouachita River, its largest tributary, the river later broadens into a complex network of marshlands surrounding the Mississippi and Atchafalaya rivers. Its waters eventually discharge into the Atchafalaya River and flow eastward or southward into the Gulf of Mexico.
In 1946, the Red River flood spilled over into Pineville because of insufficient levee height and strength. However, the taller and stronger levee held in Alexandria. Willie E. Kees Jr., the newly elected mayor of Pineville, worked to gain support for the Corps of Engineers to increase the height of the levee on the eastern side of the river to equal that in Alexandria.
Tributaries include the Little Red River, Prairie Dog Town Fork Red River, Salt Fork Red River, North Fork Red River, Pease River, Washita River, Kiamichi River, Little Wichita River, Little River, Sulphur River, Loggy Bayou (through Lake Bistineau and Dorcheat Bayou) as well as the Ouachita River (also known as the Black River at that point) not far (at Acme, Louisiana) from the mouth.