NOTE: Revised map under development following the November 2017 Environmental Assessment for segments 8 and 9. The routes shown reflect the BLM's authorized routes identified in the Record of Decision (ROD) released in November 2013 for segments 1 through 7 and 10, as well as the route identified in the January 2017 ROD for segments 8 and 9. In April 2017, the Interior Board of Land Appeals remanded the January 2017 ROD for further consideration. Learn more by viewing route information or maps.

This project is jointly proposed by Rocky Mountain Power and Idaho Power to 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.

Rocky Mountain Power and Idaho Power are building this new transmission line to provide electricity to meet increasing customer needs. It will deliver power from existing and future electric resources including renewable resources such as wind energy. In addition, the line will provide strength and reliability to the region’s transmission system.

This website contains important facts about the project, the companies and maps. Updates will be posted as new information becomes available, so check back often!

For vendor and contractor information, click here.




11/03/17 - BLM releases draft environmental assessment of routes for segments 8 and 9

The Bureau of Land Management (BLM) released a draft environmental assessment (EA) as part of its reconsideration of the January 2017 record of decision for segments 8 and 9 of the Gateway West Transmission Line Project. The BLM is accepting co...