Big Thompson River

Big Thompson River
The headwaters of the Big Thompson River are in Rocky Mountain National Park.
Big Thompson River is located in Colorado
Big Thompson River
Location of mouth
Location
CountryUnited States
StateColorado
CityGrand Lake
Physical characteristics
SourceRocky Mountains
 • coordinates40°25′41″N 105°47′29″W / 40.42806°N 105.79139°W / 40.42806; -105.79139[1]
 • elevation11,310 ft (3,450 m)[2]
MouthSouth Platte River
 • location
Near Greeley
 • coordinates
40°21′16″N 104°45′37″W / 40.35444°N 104.76028°W / 40.35444; -104.76028[1]
 • elevation
4,670 ft (1,420 m)[2]
Length78 mi (126 km)[3]
Discharge 
 • locationLoveland[4]
 • average72.5 cu ft/s (2.05 m3/s)[4]
 • minimum0.48 cu ft/s (0.014 m3/s)
 • maximum35,000 cu ft/s (990 m3/s)
Basin features
Tributaries 
 • leftNorth Fork Big Thompson River
 • rightLittle Thompson River

The Big Thompson River is a tributary of the South Platte River, approximately 78 miles (126 km) long, in the U.S. state of Colorado. Originating in Forest Canyon in Rocky Mountain National Park, the river flows into Lake Estes in the town of Estes Park and then through Big Thompson Canyon. It includes four crossings/bridges which are listed on the U.S. National Register of Historic Places.