The chief purpose of the dam is to provide water storage for irrigation in the Snake River basin in the state of Idaho as part of the Minidoka Project.

When the dam was built there was no attempt to clear the shores of the lake of standing timber, resulting in an unsightly band of dead trees when the waters rose.

This vista, and the mudflats created by drawdown of lake waters, were cited in later years in successful arguments against reservoirs in Yellowstone National Park.

[5][6] Construction personnel for the dam were housed at a temporary camp that dwarfed the nearby town of Moran.

[8][9][10][11][12][13] The dam is owned and operated by the U.S. Bureau of Reclamation, which maintains the water level above the lake's natural elevation for downstream irrigation.