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Electric Substations in Washington

785 named substations in Washington, with the highest-voltage facilities listed first. Each substation profile shows voltage class, connected transmission lines, and the datacenter candidate sites closest to it.

At a glance

Washington has 2,106 electric substation records in the HIFLD dataset, 785 of them with a station name (the other 1,321 are unnamed tap points, risers and line ends). 34 named substations operate at 345 kV or above, 31 of them at 500 kV or more. The highest recorded voltage is 500 kV and the median is 115 kV.

How is Washington's substation network split by voltage?

By maximum voltage, the named substations break down as 31 at 500 kV and above; 3 at 345–499 kV; 103 at 230–344 kV; 515 at 115–229 kV; 71 at 69–114 kV; 4 below 69 kV; 58 withvoltage not recorded. 4% of Washington's named substations operate at 345 kV or above, against 8% across all 16,654 named US substations. The state median of 115 kV is level with the national median of 115 kV.

How does Washington compare with other states?

Washington ranks 4th of 50 states and DC by number of named substations and 12th by named substations at 345 kV or above. It also has 6,019 scored datacenter candidate sites with an average DC Readiness score of 51.7 (national average 53), and an average power sub-score of 36.5 against 37.4 nationally. Most of those sites (6,017) are in the WECC market.

Which substations in Washington have the highest voltage?

SubstationMax voltageConnected linesLine owner
ASHE500 kV9BONNEVILLE POWER ADMINISTRATION
BELL500 kV18BONNEVILLE POWER ADMINISTRATION
BIG HANAFORD500 kV2BONNEVILLE POWER ADMINISTRATION
CENTRAL FERRY500 kV7BONNEVILLE POWER ADMINISTRATION
CHIEF JOSEPH500 kV14BONNEVILLE POWER ADMINISTRATION
COLUMBIA500 kV15BONNEVILLE POWER ADMINISTRATION
COLUMBIA GENERATING STATION500 kV3BONNEVILLE POWER ADMINISTRATION
COVINGTON500 kV14BONNEVILLE POWER ADMINISTRATION
CUSTER500 kV9BONNEVILLE POWER ADMINISTRATION
ECHO LAKE500 kV4BONNEVILLE POWER ADMINISTRATION
GRAND COULEE 230KV500 kV16BONNEVILLE POWER ADMINISTRATION
GRAND COULEE 500KV500 kV11BONNEVILLE POWER ADMINISTRATION
HANFORD500 kV6BONNEVILLE POWER ADMINISTRATION
LITTLE GOOSE500 kV5BONNEVILLE POWER ADMINISTRATION
LOWER GRANITE500 kV4BONNEVILLE POWER ADMINISTRATION
LOWER MONUMENTAL500 kV7BONNEVILLE POWER ADMINISTRATION
MAPLE VALLEY500 kV12CITY OF SEATTLE - (WA)
MONROE500 kV6BONNEVILLE POWER ADMINISTRATION
NAPAVINE500 kV5BONNEVILLE POWER ADMINISTRATION
OLYMPIA500 kV12BONNEVILLE POWER ADMINISTRATION
PAUL500 kV8BONNEVILLE POWER ADMINISTRATION
PHALEN GULCH500 kV3PACIFICORP
RAVER500 kV9BONNEVILLE POWER ADMINISTRATION
ROCK CREEK500 kV7PUD NO 1 OF KLICKITAT COUNTY
SACAJAWEA500 kV3BONNEVILLE POWER ADMINISTRATION
SATSOP500 kV6BONNEVILLE POWER ADMINISTRATION
SCHULTZ500 kV10BONNEVILLE POWER ADMINISTRATION
SICKLER500 kV3BONNEVILLE POWER ADMINISTRATION
SNO-KING500 kV10PUD 1 OF SNOHOMISH COUNTY
VANTAGE500 kV12PUD NO 1 OF KITTITAS COUNTY
WAUTOMA500 kV5BONNEVILLE POWER ADMINISTRATION
ROCKY REACH345 kV13PUD NO 1 OF CHELAN COUNTY
ROSS345 kV15BONNEVILLE POWER ADMINISTRATION
SNOHOMISH345 kV19PUGET SOUND ENERGY INC
MAYFIELD240 kV4CITY OF TACOMA - (WA)
MOSSYROCK PP240 kV5CITY OF TACOMA - (WA)
ADDY230 kV8BONNEVILLE POWER ADMINISTRATION
ALCOA230 kV5BONNEVILLE POWER ADMINISTRATION
ALFALFA230 kV3PACIFICORP
BEACON230 kV14AVISTA CORP
BELLINGHAM230 kV6PUGET SOUND ENERGY INC
BELLINGHAM230 kV9PUGET SOUND ENERGY INC
BENTON230 kV8BONNEVILLE POWER ADMINISTRATION
BERRYDALE230 kV8PUGET SOUND ENERGY INC
BETTAS ROAD230 kV4BONNEVILLE POWER ADMINISTRATION
BIG HORN230 kV5BONNEVILLE POWER ADMINISTRATION
BOTHELL230 kV13CITY OF SEATTLE - (WA)
BOUNDARY230 kV12BONNEVILLE POWER ADMINISTRATION
CASCADE230 kV3PUGET SOUND ENERGY INC
CHEHALIS230 kV12BONNEVILLE POWER ADMINISTRATION
COWLITZ230 kV11CITY OF TACOMA - (WA)
COWLITZ FALLS230 kV2BONNEVILLE POWER ADMINISTRATION
CRESTON NELSON230 kV3BONNEVILLE POWER ADMINISTRATION
CUSICK230 kV3BONNEVILLE POWER ADMINISTRATION
DELRIDGE230 kV2CITY OF SEATTLE - (WA)
DIABLO230 kV6CITY OF SEATTLE - (WA)
DODGE JUNCTION230 kV1PACIFICORP
DOOLEY230 kV3PUD NO 1 OF KLICKITAT COUNTY
DOUGLAS230 kV6PUD NO 1 OF DOUGLAS COUNTY
DRY GULCH230 kV6AVISTA CORP

Every named substation in Washington

All 785 named substations, grouped by voltage band.

500 kV and above · 31

345–499 kV · 3

230–344 kV · 103

115–229 kV · 515

69–114 kV · 71

below 69 kV · 4

voltage not recorded · 58

Frequently asked questions

How many electric substations are in Washington?

HIFLD records 2,106 substations in Washington, of which 785 carry a station name. That is the 4th-most named substations of any state in the dataset.

What is the highest-voltage substation in Washington?

31 named substations in Washington share the top voltage of 500 kV, including ASHE, BELL, BIG HANAFORD.

Which substation in Washington connects the most transmission lines?

SNOHOMISH has the most connected transmission lines of the named substations listed here, with 19 at up to 345 kV.

How many substations in Washington are 345 kV or higher?

34 of 785 named substations (4%) operate at 345 kV or above, compared with 8% nationally. Washington ranks 12th of 50 states and DC for named substations at that level.

How many datacenter candidate sites in Washington are at substations?

1,343 of the 6,019 scored candidate sites in Washington are substation sites — locations generated at an existing substation. Scored sites across Washington average 51.7 on the 0–100 DC Readiness scale, against 53 nationally.

Looking for a specific record? The directory lists every substation in Washington, A to Z.

More on Washington, and states with similar counts

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, “Electric substations in Washington”, https://gridcensus.com/substations/washington (data as of June 29, 2026).

Dataset updated . Screening estimates derived from public data sources.

Go deeper than the public screen

Every site and score for substations in Washington 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.

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