| Gibson Reservoir | |
|---|---|
 | |
  Gibson Reservoir | |
| Location | Teton County &Lewis & Clark County,Montana,United States |
| Coordinates | 47°36′12″N112°45′39″W / 47.60333°N 112.76083°W /47.60333; -112.76083[1] |
| Type | Reservoir |
| Primary inflows | South Fork Sun River North Fork Sun River |
| Primary outflows | Sun River |
| Built | 1926-1929[2] |
| Max. length | 4.5 miles (7.2 km) |
| Max. width | 3,500 feet (1,100 m) |
| Surface area | 1,288.8 acres (521.6 ha)[3] |
| Max. depth | 123 feet (37 m) |
| Water volume | 96,477 acre-feet (119,003,000 m3)[2] |
| Surface elevation | 4,869 feet (1,484 m)[1] |
Gibson Reservoir is a man-made body of water located just south of theBob Marshall Wilderness, 20 miles (32 km) northwest ofAugusta,Montana. It forms part of the county line betweenTeton andLewis & Clark counties. Thereservoir is formed by the concrete archGibson Dam and backs water up between ahilly pass for about 3 miles. The water in the dam is initially provided by springsnowrunoff and carried there via theNorth Fork Sun River and the South Fork Sun River right after the two join. The reservoir is mainly used forirrigation control.
