TAP208521
SubstationMontana · NORTHWESTERN ENERGY LLC - (MT)
At a glance
TAP208521 is an electric transmission substation in Montana, on NORTHWESTERN ENERGY LLC - (MT)'s transmission network. It is classified as sub-transmission (115 kv) and connects 3 transmission lines. Substation proximity is one of the strongest speed-to-power signals for siting a datacenter — interconnection distance to an energized, high-voltage bus is often the binding constraint on time-to-energization.
Voltage & classification
Ownership
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #210306 | 115 kV | NORTHWESTERN ENERGY LLC - (MT) | — | 2.0 mi |
| #210308 | 115 kV | NORTHWESTERN ENERGY LLC - (MT) | — | 0.0 mi |
| #210309 | 115 kV | NORTHWESTERN ENERGY LLC - (MT) | — | 1.6 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of TAP208521, ranked by DC Readiness. Sites this close to an energized substation carry a strong speed-to-power advantage.
| Site | Type | State | County | Voltage | Capacity | Queue wait | Score |
|---|---|---|---|---|---|---|---|
| BROADVIEW | Substation-Adjacent | MT | Golden Valley County | 500 kV | 1,000 MW | 1.1 yrs | 70.1 |
| BILLINGS | Substation-Adjacent | MT | Yellowstone County | 230 kV | 300 MW | 1.1 yrs | 67.4 |
| ALKALI CREEK | Substation-Adjacent | MT | Yellowstone County | 230 kV | 300 MW | 1.1 yrs | 67.2 |
| SHOREY ROAD | Substation-Adjacent | MT | Yellowstone County | 230 kV | 300 MW | 1.1 yrs | 67.1 |
| EC Coal Yellowstone County | Greenfield | MT | Yellowstone County | — | — | 1.1 yrs | 66.9 |
| UNKNOWN202569 | Substation-Adjacent | MT | Yellowstone County | 230 kV | 300 MW | 1.1 yrs | 66.8 |
| EC Near J E Corette Plant | Greenfield | MT | Yellowstone | — | — | 1.1 yrs | 66.7 |
| EC Near J E Corette Plant | Greenfield | MT | Yellowstone | — | — | 1.1 yrs | 66.0 |
Who owns the transmission lines at TAP208521?
The 3 connected lines listed above are owned by NORTHWESTERN ENERGY LLC - (MT). Line voltages range from 115 kV to 115 kV. Their combined recorded length is about 3.6 miles.
How do candidate sites near TAP208521 score?
The 8 highest-scoring candidate sites within about 25 miles range from 66 to 70 on the 0–100 DC Readiness scale. They fall in Golden Valley County, Yellowstone County, Yellowstone. The Montana average across 2,542 scored sites is 54.3. 815 of those Montana sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
What voltage is TAP208521 substation?
TAP208521 has a maximum voltage of 115 kV. That places it in the 115–229 kV band. The median named US substation in this dataset is 115 kV, so TAP208521 is at the national midpoint.
How many transmission lines connect to TAP208521 substation?
3 transmission lines terminate at or pass through TAP208521 in the HIFLD line data. The connected lines listed here run at 115 kV. Together the listed lines cover about 3.6 miles.
Who owns TAP208521 substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at TAP208521 belong to NORTHWESTERN ENERGY LLC - (MT). GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is TAP208521 substation located?
TAP208521 is in Montana at 45.7935, -108.4789. The datacenter candidate sites closest to it are in Golden Valley County, Yellowstone County, Yellowstone.
Are there datacenter candidate sites near TAP208521 substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of TAP208521. The highest-scoring is BROADVIEW at 70/100. Across Montana, the average DC Readiness score is 54.3.
More in Montana
About this data
Source: HIFLD Electric Substations and Transmission Lines (U.S. Department of Homeland Security), as published June 29, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: GridCensus, “TAP208521 substation, Montana”, https://gridcensus.com/substations/montana/tap208521-dded5bd8 (data as of June 29, 2026).
Dataset updated . Screening estimates derived from public data sources.
Substation attributes are derived from public HIFLD / EIA infrastructure data and may lag real-world upgrades or retirements. Voltage and connected-line counts are screening figures — confirm available capacity and interconnection terms directly with the operating utility and ISO.
Go deeper than the public screen
Every site and score for TAP208521 substation, Montana is free to browse. Pro adds Watchtower on 25 sites, alerts when new candidate sites, datacenters or interconnection-queue requests appear in your markets, score and capacity history, and CSV export. Enterprise adds team seats, weekly data files for all 147,272 sites, the REST API and an MCP server for AI tools.