The existing transmission grid across the West is aging and increasingly operating at its full capacity during peak periods of customer electric use. Idaho Power and Rocky Mountain Power (the companies) have jointly proposed the Gateway West Transmission Line Project to enhance reliability and deliver electricity from existing and new generating resources, including renewables such as wind.

The project would build and operate approximately 1,000 miles of new high-voltage transmission lines between the Windstar Substation near Glenrock, Wyoming and the Hemingway Substation near Melba, Idaho. The project would include approximately 150 miles of 230 kilovolt (kV) lines in Wyoming and approximately 850 miles of 500 kV lines in Wyoming and Idaho.

The Bureau of Land Management (BLM) is the lead federal agency that conducted the environmental review and analysis as part of the National Environmental Policy Act (NEPA) process.

Recent project milestones
  • The BLM released its Record of Decision (ROD) on November 14, 2013, for segments 1 through 7 (Windstar to Populus, Populus to Midpoint and Populus to Cedar Hill) and segment 10 (Midpoint to Cedar Hill) of the project. It identifies the BLM authorized route on public land.
  • The BLM postponed a decision on segments 8 (Midpoint to Hemingway) and 9 (Cedar Hill to Hemingway) to resolve routing in this area. The companies submitted a revised application for segments 8 and 9 in August 2014. The BLM determined that new information included in this application would require additional analysis to supplement the analysis in the 2013 final EIS for the original, 10-segment project.
  • A draft supplemental EIS for segments 8 and 9 was released March 11, 2016, and the final supplemental EIS was published on October 7, 2016.
  • The BLM released its ROD for segments 8 and 9 on January 19, 2017. The ROD identifies BLM authorized routes on public land for segments 8 and 9.
What's Ahead?

The original 2013 ROD and right-of-way grant contains many conditions and stipulations that must be met and accepted before the project can move to construction. Rocky Mountain Power and Idaho Power will continue the work necessary to meet these requirements. The 2017 ROD for segments 8 and 9 contains additional conditions and stipulations that must also be met. Rocky Mountain Power and Idaho Power will continue to meet regularly with the BLM to review progress on these conditions.

There is more work to be done to obtain state and local permits, as well as obtaining rights-of-way for the entire length of the project. Rocky Mountain Power and Idaho Power will continue evaluating the timing of next steps in the project to best meet our customer and system needs. The Companies anticipate line segments will be completed in phases between 2019 and 2024.