Mancos River

Mancos River
Mancos River, San Juan River confluence (Four Corners)
(Carrizo Mountains at southwest)
Physical characteristics
Source 
  locationConfluence of West Mancos River and East Mancos River
  coordinates37°21′30″N 108°15′12″W / 37.35833°N 108.25333°W / 37.35833; -108.25333
Mouth 
  location
Confluence with San Juan
  coordinates
36°59′00″N 108°58′50″W / 36.98333°N 108.98056°W / 36.98333; -108.98056
  elevation
4,639 ft (1,414 m)
Basin features
ProgressionSan JuanColorado

The Mancos River, formerly also El Rio de San Lazaro, is an 85.4-mile-long (137.4 km) northeast tributary of the San Juan River. It flows from the confluence of West Mancos River and East Mancos River near Mancos, Colorado and joins the San Juan near Four Corners Monument in New Mexico.

The river was named after an incident during which a horse rider hurt his hand while crossing, the word Mancos being derived from Spanish meaning "one-armed".