East Fork Cimarron River

East Fork Cimarron River
Physical characteristics
Mouth 
  location
Confluence with Middle Fork
  coordinates
38°12′15″N 107°31′11″W / 38.20417°N 107.51972°W / 38.20417; -107.51972
  elevation
9,022 ft (2,750 m)
Basin features
ProgressionCimarronGunnisonColorado

East Fork Cimarron River is a 12.6-mile-long (20.3 km) tributary of the Cimarron River in Colorado. The river's source is near Wetterhorn Peak in the Uncompahgre Wilderness of Hinsdale County. It joins the Middle Fork Cimarron River in Gunnison County to form the Cimarron River, and is impounded by Silver Jack Dam.