Duchesne River

The Duchesne River drains the south slope of the Uinta Mountains and the western Uinta Basin, flowing approximately 113 miles south and east to join the Green River near Myton, Utah — about 60 miles upstream of the Desolation Canyon put-in. It is the largest tributary of the Green between the Yampa and the Price, collecting snowmelt from the High Uintas through a network of forks — the North, West, and main Duchesne — before crossing the agricultural bottomlands of the Uintah and Ouray Reservation. The river is heavily managed for irrigation through the Central Utah Project and the Duchesne Valley water system, leaving late-summer flows significantly depleted.

The Duchesne River Formation — a late Eocene unit of fluvial sandstone and mudstone — is named for this river and is the type locality for the Duchesnean North American Land Mammal Age. The upper forks cut through Precambrian quartzite of the Uinta Mountains, the same formation exposed in Lodore Canyon on the Green.

The lower Duchesne is critical habitat for endangered native fish. Flow management agreements between the Central Utah Water Conservancy District and the Fish and Wildlife Service attempt to maintain minimum base flows for native fish during late-summer irrigation season.