Mystic Lake P-2301

General information

Waterway  West Rosebud Creek
Current status   Active license 
Type of facility Conventional Hydro
Mode of hydropower generation Reregulating
Type of permit FERC License

FERC information

FERC docket # P-2301
FERC project name Mystic Lake
Permit issued 12/12/07
Permit expiration 12/27/50

Ownership and operation

Owner Northwestern Coporation
Owner type Wholesale Power Marketer
Year first online (conventional hydro) 1925
Transmission or distribution system owner NorthWestern Energy LLC - (MT)

Power and generating capacity

Number of units 2
Total capacity from hydraulic turbine-generator units within each plant 12.0 MW
Average annual net hydropower generation 50,622.2 MWH

Download license summary for the Mystic Lake project.

The project is located on West Rosebud Creek, in Stillwater and Carbon counties, Montana. The project occupies 673.54 acres and is located entirely within Custer National Forest owned by US Forest Service.

The Mystic Lake Project has two reservoirs: Mystic Lake, created by Mystic Lake dam, also the storage reservoir; and the West Rosebud Lake, impounded by Re-regulation dam, located downstream. West Rosebud Lake is used to moderate peaking flows from the powerhouse.


License Issued 12-17-2007
License Application Filed 12-15-2006
License Effective 01-01-2010

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