Madison Dam

Brownfield

Ennis, Madison, Montana · NorthWestern Energy (MT Hydro)

Legacy capacity
9
MW

Madison Dam is a former hydro site in Ennis, Madison, Montana, retired 2019-10-01. Retired generation sites are among the most attractive datacenter redevelopment targets: the existing interconnection was sized for roughly 9 MW of generation, so the grid hookup, transmission rights, and often cooling-water access are already in place — collapsing the speed-to-power timeline versus a greenfield build.

Former use & capacity

Former useformer hydro site
Site typeretired_plant
Existing capacity9 MW
Retirement date2019-10-01
EIA plant ID#6422

Grid hookup & remediation

Nearest substation3.1 mi
OperatorNorthWestern Energy (MT Hydro)
Operator address950 Ennis Lake Road, Ennis, MT, 59729
Why this site is datacenter-attractive: a former hydro site of this scale leaves behind a high-capacity grid interconnection that a new load can re-use, frequently shaving years off the interconnection queue. Retired-plant sites also tend to be already zoned for heavy industrial use with established road, rail, and water infrastructure.

Nearby datacenter candidate sites

Scored candidate sites near Madison Dam, ranked by DC Readiness.

Candidate sites near Madison Dam
SiteTypeStateCountyVoltageCapacityQueue waitScore
DEADHEADSubstation-AdjacentMTGallatin County115 kV100 MW1.1 yrs72.2
UNKNOWN202686Substation-AdjacentMTJefferson County115 kV100 MW1.1 yrs68.4
Greenfield (THREE RIVERS - UNKNOWN202222)GreenfieldMTGallatin County115 kV100 MW1.1 yrs67.5
UNKNOWN202297Substation-AdjacentMTMadison County115 kV100 MW1.1 yrs67.3
UNKNOWN205083Substation-AdjacentMTGallatin County115 kV100 MW1.1 yrs67.2
UNKNOWN202306Substation-AdjacentMTMadison County115 kV100 MW1.1 yrs65.9
TAP207391Substation-AdjacentMTGallatin County115 kV100 MW1.1 yrs65.4
Greenfield (THREE RIVERS - MILL CREEK GENE)GreenfieldMTJefferson County230 kV300 MW1.1 yrs64.8

Nearby internet exchanges

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Dataset updated . Screening estimates derived from public data sources.

Brownfield attributes are derived from EIA retired-generator and EPA public data. Existing capacity reflects the retired plant's historical nameplate, not deliverable interconnection for a new load. Confirm reusable interconnection rights, remediation status, and site availability with the utility, ISO, and current owner.

Go deeper than the public screen

This page shows a public slice of the GridCensus dataset for Madison Dam, Ennis, Madison, Montana. Pro and Enterprise plans unlock the full 164,098-site catalog, raw sub-scores, parcel ownership, interconnection-queue detail, saved searches, and programmatic API access.