Completed in 1906, the dam is east of Rupert on county highway 400; it is 86 feet (26 m) high and nearly a mile (1.6 km) in length, with a 2,400-foot (730 m) wide overflow spillway section.

Lake Walcott State Park and the headquarters for the Minidoka National Wildlife Refuge are adjacent to the dam.

The Minidoka project brought water into the southeastern areas of Idaho near the cities of Rupert and Burley.

The powerplant installation was significant as a precursor of much larger projects on the Columbia River, including Bonneville Dam.

It was designed to generate electricity for pumping operations to support irrigation on the south bank of the Snake River.