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In 2014, NorthWestern Energy purchased 11 hydroelectric power plants, as well as Hebgen Lake reservoir, with a total generating capacity of more than 633 megawatts. The purchase from PPL Montana, included Thompson Falls Dam on the Clark Fork River; Kerr Dam on the Flathead River; Madison Dam on the Madison River; Mystic Lake Dam on West Rosebud Creek; and Hauser, Holter, Black Eagle, Rainbow, Cochrane, Ryan and Morony dams on the Missouri River. In 2015, the Confederated Salish and Kootenai Tribes acquired Kerr Dam, now called Salish-Kootenai Dam.

 
Here are the facilities:

 
Thompson Falls
on the Clark Fork River about 100 miles northwest of Missoula: Thompson Falls Dam is a seven-unit hydroelectric plant on the Clark Fork River in Thompson Falls. The units have a total generating capacity of 94 megawatts. It one of the two dams west of the continental divide.

 

 



Madison Dam
is a four-unit hydroelectric plant on the Madison River at the head of Bear Trap Canyon, about 10 miles north of Ennis, Mont. The units have a total generating capacity of 9 megawatts.

 
 

South of Madison Dam, just north of the Idaho border near Yellowstone National Park, is our Hebgen Lake storage reservoir, which is used to store water from a 905-square-mile drainage area at the headwaters of the Madison-Missouri river system, home to eight  Montana hydroelectric plants — Black Eagle, Cochrane, Hauser, Holter, Madison, Morony, Rainbow and Ryan. Hebgen is used to regulate the flow of water into the Madison-Missouri system.

 

Hauser Dam
is a six-unit hydroelectric plant on the Missouri River, about 14 miles northeast of Helena, Mont. The units have a total generating capacity of 19 megawatts.

 
 


Holter Dam
is a four-unit hydroelectric plant on the Missouri River, about 43 miles northeast of Helena, Mont. The units have a total generating capacity of 48 megawatts. It is considered a “run-of-river” project because it can generate electricity using the water that flows down the river, without the need to store additional water supplies.

 


Black Eagle Dam
is a three-unit hydroelectric plant at Black Eagle Falls on the Missouri River, about two miles downstream from Great Falls, Mont. The units have a total generating capacity of 21 megawatts.

 
 


The Rainbow Dam hydroelectric plant is located on the Missouri River, about 6 miles northeast of Great Falls, Mont. A new single-unit, 60-megawatt powerhouse was completed in early 2013, increasing the hydroelectric facility’s generating capacity by 70 percent. The new powerhouse replaces an eight-unit, 35-megawatt facility.  

 



Cochrane Dam
is a two-unit hydroelectric plant on the Missouri River, about eight miles downstream from Great Falls, Mont. The units have a total generating capacity of 64 megawatts.

 



Ryan Dam
is a six-unit hydroelectric plant on the Missouri River, about 10 miles downstream from Great Falls, Mont. The units have a total generating capacity of 60 megawatts.

 


Mystic Lake Dam is a two-unit hydroelectric plant on the West Rosebud Creek in the Beartooth Mountains, about 75 miles southwest of Billings, in southern Montana. Mystic Lake Dam is classified as a “storage generation” project because it uses the water stored in its reservoir to generate electricity.

 



Morony
, a two-unit hydroelectric plant on the Missouri River, about 15 miles northeast of Great Falls is one of the eight hydroelectric plants and one reservoir along the Missouri and Madison Rivers.

 

 

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