Dion R Holm

Dion R Holm is a 180 MW hydroelectric power plant in Tuolumne County, California, operated by City & County of San Francisco - (CA). EIA-860M lists 2 generating units here, inside CAISO. Its units entered service in 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
180.2 MW
180.2 MW net summer
Generating units
2
In service
1960
EIA plant ID
380

Where it is

Loading map…
County
Tuolumne County, California
Coordinates
37.8966, -119.9675
Balancing authority
CISO
Sector
Electric Utility

Units, technology and status

Operator of record
City & County of San Francisco - (CA)
Primary energy source
Hydro
Technologies
Conventional Hydroelectric
Status
Operating

Every plant City & County of San Francisco - (CA) reports to EIA →

Dion R Holm: FAQ

Where is Dion R Holm?
In Tuolumne County, California (CA). 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 Dion R Holm?
180 MW of nameplate capacity across 2 units, as of the EIA-860M release for 2026-07.
Who owns Dion R Holm?
EIA-860M names City & County of San Francisco - (CA) 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 Dion R Holm LLC?
Probably, but EIA-860M does not say. The survey records a plant name and a reporting entity — City & County of San Francisco - (CA) 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 "Dion R Holm LLC" usually means this site. This page shows only what EIA files, and does not assert a corporate structure it cannot see.
Is Dion R Holm still running?
EIA-860M files it as "Operating" for 2026-07. Statuses change monthly, and this page follows the monthly release.