Illinois River (Arkansas–Oklahoma)

Illinois River
The Illinois River, seen here in the upper stretches of Tenkiller Ferry Lake
Location
CountryUnited States
StatesArkansas, Oklahoma
Physical characteristics
Source 
  locationOzark Mountains
  coordinates35°51′08″N 94°17′23″W / 35.85222°N 94.28972°W / 35.85222; -94.28972 (Illinois River (source))
Mouth 
  location
Arkansas River
  coordinates
35°29′21″N 95°05′52″W / 35.48917°N 95.09778°W / 35.48917; -95.09778 (Illinois River (mouth))
  elevation
459 ft (140 m)
Length98.8 mi (159.0 km)
Discharge 
  locationGore
  average1,551 cu ft/s (43.9 m3/s)

The Illinois River is a 145-mile-long (233 km) tributary of the Arkansas River in the U.S. states of Arkansas and Oklahoma. The Osage Indians named it Ne-eng-wah-kon-dah, which translates as "Medicine Stone River". The state of Oklahoma has designated its portion as a Scenic River.