Thompson Falls on the Clark Fork River, a seven-unit, 96 megawatt facility. Built in 1915 as a complex of four dams on a natural waterfall and backing up a reservoir. The facility is seven-units with a 94 megawatt capacity. Owned by NorthWestern Energy.
Hebgen Dam on the Madison River is a storage/regulation facility for the chain of hydroelectric facilities further downstream on the Madison and Missouri Rivers. Owned by NorthWestern Energy.
Four-unit, run-of-the-river, 9-megawatt, Madison River at head of Bear Trap Canyon. Originally built in 1901 with replacement in 1905-06. Owned by NorthWestern Energy.
Six-unit, 19-megawatt, run-of-the-river, Missouri River. Completed in 1911 following failure of initial dam in 1908. Owned by NorthWestern Energy.
Noxon Rapids Dam on the Clark Fork River near the Idaho border is an earth-fill five-turbine storage facility constructed in 1955 – 59 with a capacity of 527 megawatts. Owned by Avista with a proposed merger with Hydro One.
Holter is a four-unit, 48-megawatt, run-of-the-river facility on the Missouri River. Completed in 1918. Owned by NorthWestern Energy.
Black Eagle is a three-unit, 21 megawatt, run-of-the-river dam on the Missouri River. Completed in 1891 with new dam and powerhouse rebuild in 1926-27. Owned by NorthWestern Energy.
Rainbow is a single-unit, 60-megawatt, run-of-the-river dam on the Missouri River. Completed in 1910 with eight-unit, 35-megawatt capacity. A new single-unit powerhouse was completed in 2013. Owned by NorthWestern Energy.
This dam is a two-unit, 64-megawatt, run-of-the-river facility on the Missouri River. Completed in 1958 and named for a Montana Power Company engineer. Owned by NorthWestern Energy.
Two-unit, 48-megawatt, run-of-the-river on the Missouri River. Completed in 1930. Owned by NorthWestern Energy.
This facility is a six-unit, run-of-the-river, 60-megawatt dam on the Missouri River. Completed in 1915 as Volta Dam and later renamed for John Ryan, the founder of the Montana Power Company. Owned by NorthWestern Energy.
Formerly known as Kerr Dam, this facility is a three-unit, 194-megawatt capacity dam on the Flathead River at the outlet of Flathead Lake and is considered a storage facility. Completed in 1938. Confederated Salish and Kootenai Tribes exercised an option to purchase the dam from NorthWestern Energy in 2015.
Two-unit, 12-megawatt, storage, on Rosebud Creek in Beartooth Mountains. Completed in 1925. Owned by NorthWestern Energy.
Largest earth-fill hydroelectric facility in the U.S., was started in 1933 on the Missouri River with full-pool attained about 1940. Generators were installed in the 1940s and today the facility has three generating units completed in 1951 at 105 megawatts, and two completed in 1961 at 80 megawatts. Generation is divided between the Western Interconnect and the Eastern Interconnect with one generator capable of switching between the two. Owned and operated by U.S. Army Corps of Engineers.
Built as Clark Dam in 1908 at the confluence of the Blackfoot and Clark Fork Rivers. This was a run-of-the-river facility with a capacity of about 3 megawatts. The dam backed up a great deal of metal-laden sediment dating to the flood year of 1908. The dam was decommissioned and removed between 2007 and 2010.
Also known as Broadwater Dam, on the Missouri River, was built in 1940 as a run-of-the-river irrigation facility. A 10-megawatt turbine was added in 1989. The facility is owned by the state of Montana's Department of Natural Resources and Conservation and is designated a small power production Qualifying Facility by the Federal Energy Regulatory Commission.
On the Missouri River, originally dates to 1898 with improvements to the generators in 1901. A new dam just downstream was started in 1949 and completed in 1954, which inundated the older facility. The dam's three generators deliver a capacity rated at 50 megawatts. The facility is owned by the Bureau of Reclamation. See also: www.helenahistory.org/dams.htm .
This facility on the South Fork of the Flathead River was completed in 1953 by the U.S. Army Corps of Engineers. The dam contributes control to the hydoelectric facility at Seli's Ksanka Qlispe' Dam downstream on the main Flathead River. Four generators were upgraded in the 1990s to a capacity of 428 megawatts.
On the Kootenai River was dedicated in 1975 by President Gerald Ford. The dam backs up Lake Koocanusa, which extends well into British Columbia. The dam was built and is managed by the U.S. Army Corps of Engineers and its five turbines generate 600 megawatts, which is marketed and managed by the Bonneville Power Administration. .
Yellowtail Dam on the Bighorn River on the Crow Indian Reservation was constructed in the 1960s and completed in 1967 as an irrigation, flood control, and hydroelectric facility. It is a concrete arch style facility and backs up Bighorn Reservoir well into Wyoming. Four turbines produce 250 megawatts. Owned and operated by the U.S. Bureau of Reclamation.
The images of the Madison, Hauser, Black Eagle, Cochrane, and Ryan Dam are provided from NorthWesern Energy's Hydroelectric Facilities page .
Canyon Ferry Dam Image provided by Helena History.org.