Mystic

Hydro power plant · Stillwater County, Montana

Nameplate capacity
12 MW
Rank in Montana
#50
of 73 plants
In service since
2025
May 2025

Details

Primary fuel
Hydro
Technology
Conventional Hydroelectric
Operator
NorthWestern Energy (MT Hydro)
County
Stillwater County
Generating units
2
Share of state capacity
0.16%
Rank among hydro plants in Montana
#18 of 23
EIA plant code
2192

Generating units

Individual generating units at Mystic
UnitTechnologyNameplateSummerOnlineStatus
MYS1Conventional Hydroelectric6.0 MW6.0 MW2025Operating
MYS2Conventional Hydroelectric6.0 MW6.0 MW2025Operating

Nameplate is the maximum rated output; summer capacity is what the unit can reliably deliver on a hot day, which is typically lower.

Similarly sized plants in Montana

About this data

From EIA’s inventory of operable generators, May 2026 release. Capacity is nameplate — the maximum rated output of the equipment, not what the plant actually generates over a year, which depends on how often it runs. A 12 MW solar plant and a 12 MW nuclear plant have the same entry here and produce very different amounts of electricity.

“In service since” is the earliest in-service date among the units still listed, so a site rebuilt around newer equipment can read as younger than the site itself. All Montana power plants · What Montana actually generates