278.2 MW Hydro operating in Big Horn, MT — Western Area Power Administration UGP West
278.2 MW
Nameplate Capacity
4
Generators
units
Conventional Hydroelectric
Technology
1966
Operating Since
Coordinates
45.3074, -107.9575
County
Big Horn, MT
Owner data does not fully agree across sources.
EIA typically reports the operating utility, while GEM resolves to the financial owner or parent corporation. Both can be correct.
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | U S Bureau of Reclamation | US Bureau of Reclamation | — |
| Owner(s) | U S Bureau of Reclamation | US Bureau of Reclamation [100%] | — |
| Status | Operating | operating | — |
GEM identifies the owner as US Bureau of Reclamation [100%]
This entity is not yet in the GEM ownership database — chain unavailable.
Yellowtail Dam is a dam across the Bighorn River in south central Montana in the United States. The mid-1960s era concrete arch dam serves to regulate the flow of the Bighorn for irrigation purposes and to generate hydroelectric power. The dam and its reservoir, Bighorn Lake, are owned by the U.S. Bureau of Reclamation.
Read more on WikipediaYellowtail is a 278.2 MW hydroelectric power plant located in Big Horn County, Montana. It began operating in 1966 and is owned and operated by the U.S. Bureau of Reclamation. The plant utilizes conventional hydroelectric technology and consists of four generators. As of the most recent data, Yellowtail generated 798,419 MWh annually, achieving a capacity factor of 32.7%.
Yellowtail is the fourth-largest of six hydroelectric plants in Montana, and ranks 73rd out of 194 nationally. The plant is located within the Western Electricity Coordinating Council (WECC) NERC region. The balancing authority for Yellowtail is the Western Area Power Administration UGP West.
Generated from EIA, GEM, and public data sources
NERC Region
WECC
Balancing Authority
Western Area Power Administration UGP West
Grid Voltage
230 kV
Regulatory Status
RE
Entity Type
Federal
Sector
Electric Utility
48.3K MWh
Latest Month
798.4K MWh
Annual Generation
32.7%
Capacity Factor
No financial data available for this plant.
This plant is outside organized wholesale electricity markets (ISOs/RTOs). Nodal pricing data is not available.
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Bighorn River near Fort Smith, Montana
Water resources monitoring site on the Bighorn River below the Yellowtail Afterbay Dam near Fort Smith, MT.
Last updated 2026-03-14
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