Red River of the South

Red River
Red River looking east, north of Bonham, Texas: Texas is to the right, Oklahoma is on the left, and the border between the two states runs along the south (right) bank of the river.
Map of the Red River watershed
Native name	Bah'hatteno
Other name(s)	Rivière Rouge (former French name)
Country	United States
States	Texas  Oklahoma  Arkansas  Louisiana
Basin features
Main source	Harmon County, Oklahoma 1,535 ft (468 m) 34°34′35″N 99°57′54″W / 34.57639°N 99.96500°W / 34.57639; -99.96500
River mouth	Atchafalaya/Mississippi River 30 ft (9.1 m) 31°01′10″N 91°44′52″W / 31.01944°N 91.74778°W / 31.01944; -91.74778Coordinates: 31°01′10″N 91°44′52″W / 31.01944°N 91.74778°W / 31.01944; -91.74778
Basin size	65,595 sq mi (169,890 km2)
Physical characteristics
Length	1,360 mi (2,190 km)
Discharge	Location: mouth; max and min at Alexandria, LA Minimum rate: 1,472 cu ft/s (41.7 m3/s) Average rate: 57,000 cu ft/s (1,600 m3/s) Maximum rate: 233,000 cu ft/s (6,600 m3/s)

The Red River, or sometimes the Red River of the South, is a major tributary of the Mississippi and Atchafalaya rivers in the southern United States of America. The river was named for the red-bed country of its watershed. It is one of .

"The Mexicans and Indians on the borders of Mexico are in the habit of calling any river, the waters of which have a red appearance, 'Rio Colorado', or Red river", observed R.B. Marcy in 1853. The Red River formed part of the US-Mexico border from the Adams-Onís Treaty (in force 1821) until the Texas Annexation and the Treaty of Guadalupe Hidalgo.

The Red River is the second-largest river basin in the southern Great Plains. It rises in two branches (forks) in the Texas Panhandle and flows east, where it acts as the border between the states of Texas and Oklahoma. It forms a short border between Texas and Arkansas before entering Arkansas, turning south near Fulton, Arkansas and flowing into Louisiana, where it flows into the Atchafalaya River. The total length of the river is 1,360 miles (2,190 km), with a mean flow of over 57,000 cubic feet per second (1,600 m³/s) at the mouth.

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 southern and largest 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. (The names mean "Hard Wood" and "White Land", respectively, in Spanish.)