ONTARIO
SubstationOregon · IDAHO POWER CO
At a glance
ONTARIO is an electric transmission substation in Oregon, on IDAHO POWER CO's transmission network. It is classified as high-voltage (230 kv) and connects 9 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
Connected transmission lines
Lines terminating at or passing through this substation, by HIFLD line ID, highest voltage first.
| Line ID | Voltage | Owner | Status | Length |
|---|---|---|---|---|
| #203489 | 230 kV | IDAHO POWER CO | — | 17.4 mi |
| #208519 | 230 kV | IDAHO POWER CO | — | 20.9 mi |
| #203611 | 138 kV | IDAHO POWER CO | — | 3.2 mi |
| #203616 | 138 kV | IDAHO POWER CO | — | 12.3 mi |
| #208506 | 115 kV | IDAHO POWER CO | — | 5.5 mi |
| #208507 | 115 kV | IDAHO POWER CO | — | 2.7 mi |
| #208515 | 115 kV | IDAHO POWER CO | — | 2.6 mi |
| #203619 | 69 kV | IDAHO POWER CO | — | 15.9 mi |
| #203610 | 69 kV | IDAHO POWER CO | — | 2.5 mi |
Nearby datacenter candidate sites
Scored candidate sites within roughly 25 miles of ONTARIO, 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 |
|---|---|---|---|---|---|---|---|
| UNKNOWN202541 | Substation-Adjacent | ID | Canyon County | 230 kV | 300 MW | 5.0 yrs | 62.9 |
| CALDWELL | Substation-Adjacent | ID | Canyon County | 230 kV | 300 MW | 5.0 yrs | 62.6 |
| OZ Canyon | Greenfield | ID | Canyon | — | — | 5.0 yrs | 61.3 |
| LANGLEY | Substation-Adjacent | ID | Payette County | 230 kV | 300 MW | 5.0 yrs | 60.0 |
| EC FFE Payette County | Greenfield | ID | Payette County | — | — | 5.0 yrs | 59.8 |
| ONTARIO | Substation-Adjacent | OR | Payette County | 230 kV | 300 MW | 3.5 yrs | 59.2 |
| WILIS | Substation-Adjacent | ID | Canyon County | 138 kV | 100 MW | 5.0 yrs | 58.4 |
| OZ Canyon | Greenfield | ID | Canyon | — | — | 5.0 yrs | 58.4 |
How does ONTARIO compare with other substations in Oregon?
Oregon has 1,414 substation records in HIFLD, of which 554 carry a station name; the rest are unnamed tap points, risers and line ends. 76 named substations in the state are in ONTARIO's 230–344 kV band (14% of named stations). 34 sit in a higher band. 34 named substations in Oregon operate at 345 kV or above. The highest voltage recorded in the state is 1,000 kV, and the state median is 115 kV.
Who owns the transmission lines at ONTARIO?
The 9 connected lines listed above are owned by IDAHO POWER CO. Line voltages range from 69 kV to 230 kV. Their combined recorded length is about 83 miles.
How do candidate sites near ONTARIO score?
The 8 highest-scoring candidate sites within about 25 miles range from 58 to 63 on the 0–100 DC Readiness scale. They fall in Canyon County, Canyon, Payette County. The Oregon average across 2,430 scored sites is 53.1. 844 of those Oregon sites are classed as substation sites (candidate locations generated at an existing substation).
Frequently asked questions
What voltage is ONTARIO substation?
ONTARIO has a maximum voltage of 230 kV and a minimum of 69 kV. That places it in the 230–344 kV band. The median named US substation in this dataset is 115 kV, so ONTARIO is above the national midpoint.
How many transmission lines connect to ONTARIO substation?
9 transmission lines terminate at or pass through ONTARIO in the HIFLD line data. The connected lines listed here run at 230 kV, 138 kV, 115 kV, 69 kV. Together the listed lines cover about 83 miles.
Who owns ONTARIO substation?
HIFLD does not publish substation owners directly. Most of the transmission lines that end at ONTARIO belong to IDAHO POWER CO. GridCensus derives this from the line data, so confirm ownership with the utility for anything contractual.
Where is ONTARIO substation located?
ONTARIO is in Oregon at 44.0525, -116.9780. The datacenter candidate sites closest to it are in Canyon County, Canyon, Payette County.
Are there datacenter candidate sites near ONTARIO substation?
GridCensus lists at least 8 scored candidate sites within roughly 25 miles of ONTARIO. The highest-scoring is UNKNOWN202541 at 63/100. Across Oregon, the average DC Readiness score is 53.1.
Other 230 kV substations in Oregon
- MCLOUGHLIN· 14 lines
- SHERWOOD· 12 lines
- PAC TROUTDALE· 11 lines
- CHEMAWA· 10 lines
- KLONDIKE SCHOOLHOUSE· 10 lines
- REDMOND· 10 lines
- SAINT MARYS· 10 lines
- BETHEL· 9 lines
- All named substations in Oregon· 554 stations
- Datacenter candidate sites in Oregon· 2,430 sites
- Brownfield and retired plant sites in Oregon
- Substations by state
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, “ONTARIO substation, Oregon”, https://gridcensus.com/substations/oregon/ontario-cfe51e2d (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 ONTARIO substation, Oregon 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.