Hauser Dam, Hydroelectric gravity dam in Lewis and Clark County, Montana.

Hauser Dam is a straight gravity dam on the Missouri River, about 14 miles northeast of Helena, Montana. The present structure, 700 feet long and 80 feet high, was built from 1908 and opened in 1911, replacing a steel dam that failed in 1908. Its powerhouse holds six generators with a combined capacity of 17 MW, and it operates as a run-of-the-river dam, generating power without storing extra water behind it.

Samuel T. Hauser's Missouri River Power Company built the first dam here between 1905 and 1907: a steel structure on masonry footings, designed by J. F. Jackson and erected by the Wisconsin Bridge and Iron Company. On 14 April 1908 water undermined the footings and a 90-metre section tore loose, sending a 7.5 to 9-metre flood wave downstream. The present dam was built on the same site from 1908 and opened in 1911.

The dam bears the name of Samuel Thomas Hauser, a territorial governor of Montana who led the Missouri River Power Company during the initial construction.

The dam sits about 14 miles northeast of Helena, reached by road along the Missouri River. The structure is an active hydroelectric facility, so the powerhouse and dam crest are not open to the public; viewing is from nearby public roads and pullouts. Hauser Lake stretches 25 miles upstream and has a surface area of 3,800 acres, with boat ramps and shoreline access for fishing and boating.

Fragments of the failed 1907 steel dam could still be found along the banks of the Missouri River at the end of the 20th century. The steel structure itself held firm in 1908; it was the masonry footings on the gravel riverbed that gave way.