Gibson Reservoir

Gibson Reservoir is a man-made body of water located just south of the Bob Marshall Wilderness, 20 miles (32 km) northwest of Augusta, Montana. It forms part of the county line between Teton and Lewis & Clark counties. The reservoir is formed by the concrete arch Gibson Dam and backs water up between a hilly pass for about 3 miles. The water in the dam is initially provided by spring snow runoff and carried there via the North Fork Sun River and the South Fork Sun River right after the two join. The reservoir is mainly used for irrigation control.

Gibson Reservoir
Gibson Reservoir
Location	Teton County & Lewis & Clark County, Montana, United States
Coordinates	47°36′12″N 112°45′39″W[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]