Arkansas River

Arkansas River
Arkansas River headwaters in Colorado
The Arkansas River flows through Colorado, Kansas, Oklahoma, and Arkansas, and its watershed also drains parts of Texas, New Mexico and Missouri.
Location
Country	United States
State	Colorado, Kansas, Oklahoma, Arkansas
Region	Great Plains
Cities	Pueblo, CO, Wichita, KS, Tulsa, OK, Muskogee, OK, Fort Smith, AR, Little Rock, AR, Pine Bluff, AR
Physical characteristics
Source	Confluence of East Fork Arkansas River and Tennessee Creek
• location	Near Leadville, Rocky Mountains, Colorado
• coordinates	39°15′30″N 106°20′38″W / 39.25833°N 106.34389°W / 39.25833; -106.34389[1]
• elevation	9,728 ft (2,965 m)
Mouth	Mississippi River
• location	Franklin Township, Desha County, near Napoleon, Arkansas
• coordinates	33°46′30″N 91°6′30″W / 33.77500°N 91.10833°W / 33.77500; -91.10833[2][1]
• elevation	108 ft (33 m)[3][1]
Length	1,469 mi (2,364 km), West-east[4]
Basin size	168,000 sq mi (440,000 km2)[5]
Discharge
• location	Little Rock, AR[6]
• average	39,850 cu ft/s (1,128 m3/s)[6]
• minimum	1,141 cu ft/s (32.3 m3/s)
• maximum	536,000 cu ft/s (15,200 m3/s)
Basin features
River system	Mississippi River watershed
Tributaries
• left	Fountain Creek, Pawnee River, Little Arkansas River, Walnut River, Verdigris River, Neosho River
• right	Cimarron River, Salt Fork Arkansas River, La Flecha, Canadian River, Poteau River

The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in Colorado, specifically the Arkansas River Valley. The headwaters derive from the snowpack in the Sawatch and Mosquito mountain ranges. It flows east into Kansas and finally through Oklahoma and Arkansas, where it meets the Mississippi River.

At 1,469 miles (2,364 km), it is the sixth-longest river in the United States,^[7] the second-longest tributary in the Mississippi–Missouri system, and the 45th longest river in the world. Its origin is in the Rocky Mountains in Lake County, Colorado, near Leadville. In 1859, placer gold discovered in the Leadville area brought thousands seeking to strike it rich, but the easily recovered placer gold was quickly exhausted.^[8] The Arkansas River's mouth is at Napoleon, Arkansas, and its drainage basin covers nearly 170,000 square miles (440,000 km²).^[5] Its volume is much smaller than the Missouri and Ohio rivers, with a mean discharge of about 40,000 cubic feet per second (1,100 m³/s).

The Arkansas from its headwaters to the 100th meridian west formed part of the U.S.–Mexico border from the Adams–Onís Treaty (in force 1821) until the Texas Annexation or Treaty of Guadalupe Hidalgo.