Black Eagle Dam, Gravity dam on Missouri River in Cascade County, Montana.

Black Eagle Dam is a concrete gravity weir on the Missouri River in Great Falls, Montana, 782 feet long and 34.5 feet high, with a flat deck and railing along its crest. Water spills evenly over the full length of the crest in a white curtain onto the dark rock below. Its powerhouse holds three turbines, and the reservoir behind it, about 2 miles long, is called the Long Pool.

Montana Power Company built the current concrete structure in 1927 to replace the original timber-and-rock dam from 1890. The older structure remains submerged beneath the reservoir today.

The dam helped Great Falls earn the nickname 'The Electric City' because it was the first hydroelectric facility in Montana and on the Missouri River. This role made the town an early center for power generation in the region.

The dam sits on the Missouri River in Great Falls, where the crest and its railed walkway are visible from the riverbanks; the walkway itself is kept for maintenance staff reaching the gates. The reservoir, long called the Long Pool, runs about 2 miles (3.2 km) upstream. The structure's height is limited by the city's water and sewage works upstream, which would be flooded by a taller dam.

The falls were first called "Upper Pitch" by the expedition; Thomas P. Roberts, a survey engineer for the Northern Pacific Railway, formally named them Black Eagle Falls in 1872 after the eagle's nest Lewis recorded on a cottonwood tree on an island in the river.