Garrison
Garrison is a 583 MW hydroelectric power plant in Mercer County, North Dakota, operated by USACE-Omaha. EIA-860M lists 5 generating units here, inside SPP. Its units entered service between 1956 and 1960.
As of 2026-07 (inventory dated 2026-07-31) · EIA-860M Preliminary Monthly Electric Generator Inventory · eia.gov/…/july_generator2026.xlsx · eia.gov/…/eia860m
- Nameplate capacity
- 583.4 MW
- 510 MW net summer
- Generating units
- 5
- In service
- 1956–1960
- EIA plant ID
- 2815
Where it is
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- County
- Mercer County, North Dakota
- Coordinates
- 47.4945, -101.4115
- Balancing authority
- SWPP
- Sector
- Electric Utility
Units, technology and status
- Operator of record
- USACE-Omaha
- Primary energy source
- Hydro
- Technologies
- Conventional Hydroelectric
- Status
- Operating
Garrison: FAQ
- Where is Garrison?
- In Mercer County, North Dakota (ND). The map on this page is placed at the coordinates EIA files for the plant, which locate the site rather than any individual unit.
- How big is Garrison?
- 583 MW of nameplate capacity across 5 units, as of the EIA-860M release for 2026-07.
- Who owns Garrison?
- EIA-860M names USACE-Omaha as the reporting entity. That is the operator of record on the survey, which is not always the ultimate owner.
- Is this the same as Garrison LLC?
- Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — USACE-Omaha here — not the project company that holds the asset. Project companies are commonly registered as an LLC carrying the plant's name, so a search for "Garrison LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
- Is Garrison still running?
- EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.