🏛️ Issues and Advocacy Training
Courses › Western Grid Projects: CAISO, Markets, SWIP-N and Hemingway

Lesson 7 of 9 · about 19 minutes

Hemingway: Boardman to Hemingway and Gateway West

You'll be able to

  • Locate the Hemingway substation and explain why so many lines meet there
  • State B2H's owners, approvals, construction progress and target date as of October 2026
  • List the Gateway West segments in southern Idaho with their target dates
  • Explain why reported line lengths differ and which number to use

If Midpoint is the hub that ties south central Idaho to Nevada, Hemingway is the one that ties southwest Idaho to Oregon and the Northwest. The BLM describes the substation as near Melba, about 20 miles southwest of Boise, in western Owyhee County. An existing 500 kV line runs from Midpoint through Hemingway toward Summer Lake, Oregon. Boardman to Hemingway, under construction, ends there. So do two planned Gateway West routes from the east. Nearly every large transmission plan for the Treasure Valley's growth runs through this one fenced yard in the sagebrush.

Boardman to Hemingway

ItemFigure, as of October 2026Source
EndpointsLonghorn station near Boardman, Oregon, to Hemingway substation, IdahoPUC Order 35838; ODOE
LengthAbout 270.8 miles, single-circuit 500 kV, per Oregon's siting agencyODOE
CountiesMorrow, Umatilla, Union, Baker and Malheur in Oregon; Owyhee in IdahoODOE
OwnersIdaho Power about 45.45 percent, PacifiCorp about 54.55 percent, after BPA's exitPUC Order 35838
Idaho approvalCertificate, Order No. 35838, June 30, 2023 (case IPC-E-23-01)Idaho PUC
Oregon approvalFinal order on site certificate September 27, 2022; amended September 2023 and August 2024ODOE
ConstructionIdaho Power notified Oregon on July 10, 2025 that the start-of-construction threshold was met. June 2026: roads 52 percent, pads 56 percent, towers about 23 percent; over 400 workers; contractor Quanta Infrastructure Solutions GroupEFSC staff report
TargetCivil and foundation work by end of 2026; mechanical completion by end of 2027. PacifiCorp lists in-service in the fourth quarter of 2027EFSC; PacifiCorp APR

The ownership history matters for Idaho ratepayers. Order No. 35838 describes the original shares as Idaho Power 21.21 percent, BPA 24.24 percent and PacifiCorp 54.55 percent. Under a 2023 agreement, Idaho Power took over BPA's share and BPA left the project. That more than doubled Idaho Power's stake, and its customers' exposure. The order itself contains a typo, listing PacifiCorp's post-agreement share as 55.55 percent, which with 45.45 would total 101 percent. Use 54.55.

The project's schedule has slipped. When the PUC granted the certificate in June 2023, the planned in-service date was June 1, 2026. Idaho Power's 2025 resource plan, as covered in the power grid course's reliability lesson, targeted the end of 2027, which matches Oregon's latest construction update and PacifiCorp's report.

Example: reading a progress report

Oregon's June 2026 update gave percentages, not counts. Use them carefully.

  • Towers complete: about 23 percent. Remaining: 100 minus 23 = 77 percent.
  • Time from the June 2026 report to the end-of-2027 mechanical completion target: about 18 months.
  • If tower work started in earnest around mid-2025, roughly 12 months produced 23 percent, about 1.9 points a month. At that pace, 77 points takes 77 / 1.9 = about 40 months, well past the target.
  • But the update says roads and pads, which come first, were over half done. Tower erection speeds up once pads are ready.

The arithmetic doesn't prove a delay. It tells you what to ask: how many towers are scheduled per month from here, and what happens to the date if crews fall short.

How the PUC guarded Idaho customers on B2H

Lesson 4 covered the cost terms: a soft cap at the company's estimate, a with-and-without-delay cost comparison if delays require mitigation, and a showing of other funding sources at recovery time. The order also lists the intervenors: the Idaho Irrigation Pumpers Association, the Industrial Customers of Idaho Power, the City of Boise, Micron Technology and the Idaho Conservation League. When Idaho Power files to put B2H in rates, those are the parties most likely to test its numbers.

The opposition, mostly in Oregon

Most organized opposition to B2H has come from the Oregon end. The Stop B2H Coalition describes itself as a grassroots group of nearly 1,000 people fighting the line through northeast Oregon. Its site describes 1,200 towers up to 200 feet tall, 305 miles and a cleared path at least 250 feet wide; those are the coalition's figures. The coalition reports it asked Oregon regulators in 2025 to revoke the utilities' authority to condemn land, arguing PacifiCorp had changed the line's purpose, and that regulators upheld the approval in November 2025. Its August 2026 newsletter announced it was becoming Frontier Resilient Energy and Equity. In Idaho, the B2H segment runs only through Owyhee County to Hemingway, and opposition has been far quieter.

Gateway West: the long game across southern Idaho

Gateway West was proposed jointly by Idaho Power and Rocky Mountain Power to connect Wyoming to Midpoint and Hemingway. In 2016 the BLM published routes for the final Idaho segments, 8 and 9, each more than 125 miles, ending at Hemingway; the preferred route crossed 17.6 miles of the Morley Nelson Snake River Birds of Prey National Conservation Area. PacifiCorp reports the BLM right-of-way grant for that area was issued August 8, 2018.

PacifiCorp's 2026 progress report to WECC lists the southern Idaho pieces:

SegmentMilesOwnerStatus / target
Midpoint to Hemingway, circuit 1Not statedPacifiCorpIn service since July 2010
Midpoint to Hemingway, circuit 2126PacifiCorp and Idaho PowerFourth quarter 2028
Cedar Hill to Hemingway161PacifiCorp and Idaho Power2036 at earliest
Cedar Hill to Midpoint34PacifiCorp and Idaho Power2036 at earliest
Populus to Cedar Hill118PacifiCorpFourth quarter 2036 at earliest
Populus to Borah55PacifiCorp2036 at earliest
Borah to Midpoint (convert existing line to 500 kV)88Idaho Power2036 at earliest

Add the future segments with stated miles: 126 + 161 + 34 + 118 + 55 + 88 = 582 miles of new or upgraded 500 kV line in southern Idaho on PacifiCorp's list, all but one of them a decade out. A 2036 date for a segment first studied more than ten years ago is a plan. Treat it like one. Track the next progress report to see whether the dates move.

Common mix-ups

  • Claim: B2H is an Oregon project that Idaho customers won't pay for. What the evidence shows: Idaho Power owns about 45 percent, and its share goes to its customers after prudence review.
  • Claim: B2H was supposed to be done in 2026, so it's failed. What the evidence shows: The date slipped from June 2026 to the end of 2027. Construction is underway. The open questions are cost and schedule.
  • Claim: Gateway West is being built now across southern Idaho. What the evidence shows: Only the second Midpoint to Hemingway circuit has a near-term date, the end of 2028. The rest are listed for 2036 or later.

Reporting angle

  • Read each Oregon Energy Facility Siting Council construction update. They give percentages, workforce and compliance findings, such as the April 2026 weed wash station violation.
  • Ask Idaho Power for the current B2H cost estimate and compare it with the soft cap set in Order 35838.
  • Ask Owyhee County for any permits, road agreements and tax assessments tied to B2H and the Hemingway substation.
  • Ask what Midpoint to Hemingway circuit 2 is for, who pays and whether it needs a new Idaho certificate.
  • Numbers to check: tower count completed, Idaho Power's share of installed cost, in-service date, and new transfer capability at Hemingway.

Research angle

Check yourself

1. Where is the Hemingway substation?

2. After BPA left the B2H project, what were the approximate ownership shares?

3. According to Oregon's June 2026 construction update, about what share of B2H towers were complete?

4. PacifiCorp's 2026 report to WECC lists the second Midpoint to Hemingway 500 kV circuit for which in-service target?

5. Why do sources give B2H lengths of about 271, 290, 300 and 305 miles?

Terms in this lesson

B2H
Boardman to Hemingway, a 500 kV line from the Longhorn station near Boardman, Oregon to the Hemingway substation in southwest Idaho.
Energy Facility Siting Council
Oregon's board that issues site certificates for large energy facilities, including B2H's Oregon segment.
Gateway West
A long-planned set of 500 kV segments from Wyoming across southern Idaho to Midpoint and Hemingway, jointly proposed by Idaho Power and Rocky Mountain Power.
Series compensation
Equipment that lets a long line carry more power by offsetting part of its natural impedance.
National Conservation Area
A federally designated area managed by the BLM for specific values; Gateway West segments cross the Morley Nelson Snake River Birds of Prey NCA.

Full glossary

Sources