Big Thompson River

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Big Thompson River
The headwaters of the Big Thompson River are in Rocky Mountain National Park.
Location of mouth
Location
Country	United States
State	Colorado
City	Grand Lake
Physical characteristics
Source	Rocky Mountains
• coordinates	40°25′41″N 105°47′29″W / 40.42806°N 105.79139°W / 40.42806; -105.79139[1]
• elevation	11,310 ft (3,450 m)[2]
Mouth	South 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]
Length	78 mi (126 km)[3]
Discharge
• location	Loveland[4]
• average	72.5 cu ft/s (2.05 m3/s)[4]
• minimum	0.48 cu ft/s (0.014 m3/s)
• maximum	35,000 cu ft/s (990 m3/s)
Basin features
Tributaries
• left	North Fork Big Thompson River
• right	Little 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.