Green River (Colorado River tributary)

Green River
Seeds-kee-dee-Agie
The Green River near Canyonlands National Park
Green River watershed
Location
CountryUnited States
StateWyoming, Colorado, Utah
CitiesGreen River, Wyoming, Green River, Utah
Physical characteristics
SourceWind River Range
 • locationWyoming
 • coordinates43°09′13″N 109°40′18″W / 43.15361°N 109.67167°W / 43.15361; -109.67167
MouthColorado River
 • location
Canyonlands National Park, San Juan County, Utah
 • coordinates
38°11′21″N 109°53′07″W / 38.18917°N 109.88528°W / 38.18917; -109.88528
Length730 mi (1,170 km)
Basin size48,100 sq mi (125,000 km2)
Discharge 
 • locationGreen River, Utah
 • average6,121 cu ft/s (173.3 m3/s)
 • minimum380 cu ft/s (11 m3/s)
 • maximum68,100 cu ft/s (1,930 m3/s)
Basin features
Tributaries 
 • leftBlacks Fork, Henrys Fork, Duchesne River, Price River, San Rafael River
 • rightNew Fork River, Big Sandy River, Yampa River, White River
TypeWild, Scenic, Recreational
DesignatedMarch 12, 2019

The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of the U.S. states of Wyoming, Utah, and Colorado. The Green River is 730 miles (1,170 km) long, beginning in the Wind River Range of Wyoming and flowing through Wyoming and Utah for most of its course, except for a short segment of 40 miles (64 km) in western Colorado. Much of the route traverses the arid Colorado Plateau, where the river has carved some of the most spectacular canyons in the United States. The Green is slightly smaller than Colorado when the two rivers merge but typically carries a larger load of silt. The average yearly mean flow of the river at Green River, Utah is 6,121 cubic feet (173.3 m3) per second.

The status of the Green River as a tributary of the Colorado River came about mainly for political reasons. In earlier nomenclature, the Colorado River began at its confluence with the Green River. Above the confluence, Colorado was called the Grand River. In 1921, U.S. Representative Edward T. Taylor of Colorado petitioned the Congressional Committee on Interstate and Foreign Commerce to rename the Grand River as the Colorado River. On July 25, 1921, President Warren G. Harding signed House Joint Resolution 32 - To change the name of the Grand River in Colorado and Utah to the Colorado River, over the objections of the congressional delegations of the states of Wyoming and Utah and the United States Geological Survey, which noted that the drainage basin of the Green River was more extensive than that of the Grand River, although the Grand commonly carried a higher volume of water at its confluence with the Green.

The Green River is the subject of the song "Green River" by C.W. McCall.