It impounds the Snake River in a reservoir named Milner Lake.

[3] Ira Burton Perrine, a local rancher, chose the site and recruited financial backers, including Salt Lake City banker Stanley B. Milner and eastern investors Frank H. Buhl and Peter L. Kimberly.

The Buhl-Kimberly Corporation built the dam and the Twin Falls Canal in 1903–1905.

[4] Milner Dam's primary purpose is irrigation but it also produces hydroelectricity.

The Snake River below Milner Dam is often allowed to run dry during periods of low flow as water is diverted to agricultural uses.