West of Hemingway

Completed segment

Segment A – Wallula to McNary

Project overview

The project was initiated and completed to support continued reliable, safe and cost-effective electricity to customers, provide needed customer transmission service, and support new renewable energy development. Construction of the line was initiated in 2018 for the new transmission line between our Wallula Substation in Washington and Bonneville Power Administration’s McNary Substation near Umatilla, Oregon. The transmission line was originally planned to also connect Wallula with an existing substation in Walla Walla Washington. That section, however, is not scheduled to proceed at this time. The 30 mile, 230 kilovolt line between Wallula and McNary was constructed on a 125 foot-wide right-of-way. We worked to minimize impacts to the community and local environment during project development, construction and maintenance.

Project timeline

Placed in service January 31, 2019

Segment in progress

Segment H – Boardman to Hemingway

Project overview

Our Energy Gateway transmission expansion investment is intended to better integrate our company's East and West control areas. Building a line west into Oregon from the Hemingway Substation near Melba, Idaho will increase system flexibility and reliability to serve customers. While originally proposed as an approximately 375 mile, single-circuit 500-kilovolt transmission line from the Hemingway substation to a substation near Klamath Falls, Oregon, we pursued joint development opportunities with regional entities on alternatives to this proposed configuration. To that end, in January 2012, we signed a permit funding agreement with Idaho Power and Bonneville Power Administration on the proposed Boardman to Hemingway line.

Project timeline

Transmission options for “Boardman to Hemingway” are being considered from among alternative projects and will be brought into service as soon as appropriate for PacifiCorp customers. For more information please refer to the project websites for Idaho Power’s Boardman to Hemingway project.

  • Bureau of Land Management Record of Decision issued November 17, 2028
  • U.S. Forest Service Record of Decision issued November 13, 2018
  • U.S. Department of Defense Navy Record of Decision issued September 25, 2019
  • Oregon Energy Facilities Siting Council Draft Project Order issued July 2, 2020
  • Oregon permitting process moved to Contested Case process to be followed by the final order
  • Planned in service July 2026

Additional information about the project

The proposed Boardman to Hemingway transmission line is a 500 kilovolt line that would run approximately 300 miles from a new substation proposed near Boardman, Oregon, to the Hemingway substation near Melba, Idaho, southwest of Boise, Idaho. The agreement between the three companies provides funding for environmental review and permitting, ensuring continued consideration of the project.

Public input is an important part of this process and will be welcomed at all stages of this project. To contact us about this project, please call 801-220-4221 or email ConstructionProjects@pacificorp.com. Please be sure to include the project name – "Boardman to Hemingway" – in your inquiry.


(Updated March 2021)