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Island Park

Hydro power plant · Fremont County, Idaho

Nameplate capacity
4.8 MW
Rank in Idaho
#111
of 155 plants
In service since
1994
April 1994

Details

Primary fuel
Hydro
Technology
Conventional Hydroelectric
Operator
Fall River Rural Elec Coop Inc
County
Fremont County
Generating units
2
Share of state capacity
0.07%
Rank among hydro plants in Idaho
#45 of 76
EIA plant code
4204

Generating units

Individual generating units at Island Park
UnitTechnologyNameplateSummerOnlineStatus
HY1Conventional Hydroelectric2.4 MW2.4 MW1994Operating
HY2Conventional Hydroelectric2.4 MW2.4 MW1994Operating

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 Idaho

Salmon DieselOther5.0 MW
Dietrich DropHydro4.8 MW
Barber DamHydro4.1 MW
Elmore BESSBattery storage4.0 MW

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 4.8 MW solar plant and a 4.8 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 Idaho power plants · What Idaho actually generates