The Verdigris River // is a tributary of the Arkansas River in southeastern Kansas and northeastern Oklahoma in the United States. It is about 310 miles (500 km) long. Via the Arkansas, it is part of the Mississippi River watershed.
The Verdigris is formed near Madison, Kansas, by the convergence of two short headwaters streams, its North and South forks, and flows generally southward throughout its course. South of Coffeyville, the river enters Oklahoma. It joins the Arkansas River near Muskogee, about a mile upstream of the mouth of the Neosho River.
The river is mentioned in accounts by Zebulon Pike (1806), Thomas Nuttall (1818), and because of the fur trade had numerous trading posts along its route. The river is also mentioned in the book Little House on the Prairie written by Laura Ingalls Wilder, of her memories when the family moved to Kansas from Wisconsin. The name is derived from the Spanish words verde, meaning "green," and gris, meaning "grey." According to the Encyclopædia Britannica the name may be derived from a gray-green substance resembling a copper ore. In the treaty of 1834 with the Cherokee Indians, the river was named as a part of the boundary of their lands.
Dams and transportation 
Several dams built by the U.S. Army Corps of Engineers cause the Verdigris to form Toronto Lake near Toronto, Kansas and Oologah Lake near Oologah, Oklahoma. More dams and reservoirs are downsteam along the Arkansas River.
From just north of Catoosa, Oklahoma to its confluence with the Arkansas, barge traffic is maintained on the river as part of the McClellan-Kerr Navigation System, which consists of a series of locks and dams on the Arkansas River and the Verdigris River and which enables commercial navigation between the Tulsa, Oklahoma, area and the Mississippi River, and thence to the Gulf of Mexico.
Cities and towns along the river 
- Altoona, Kansas
- Benedict, Kansas
- Catoosa, Oklahoma
- Coffeyville, Kansas
- Independence, Kansas
- Madison, Kansas
- Neodesha, Kansas
- Okay, Oklahoma
- Oologah, Oklahoma
- Toronto, Kansas
- Nowata, Oklahoma
See also 
- U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map, accessed May 31, 2011
- Brittanica Online Encyclopaedia . "Verdigris River." Accessed September 4, 2011. 
- ""Verdigris River," Kansas: a cyclopedia of state history" (English). Retrieved 2007-03-14.
- Environmental News Service. "Raging Floodwaters Cause Kansas Refinery Oil Spill." July 3, 2007. Accessed September 4, 2007.