Segment B - Populus to Terminal

Project Overview

Populus to Terminal transmission line construction

Providing safe, reliable electrical service at reasonable rates is our commitment to customers. In 2007 the company launched the Energy Gateway Transmission Expansion Project, a major initiative to increase the system’s electrical capacity to serve the needs of our customers. The first segment of that expansion, the Populus to Terminal transmission line, was completed in 2010.

Extending from southeast Idaho into northern Utah, the Populus to Terminal transmission line adds a new double-circuit, 345,000-volt transmission line stretching approximately 135 miles from the new Populus substation near Downey, Idaho, to the existing Terminal substation near the Salt Lake City airport.

With individual customer electricity use 26 percent higher today than 20 years ago, this transmission line is a critical piece of infrastructure to meet this increasing need. The Populus to Terminal segment was constructed in two sections. The first section, connecting Ben Lomond and Terminal substations, was completed and put into service for customers in March 2010. The second section connects the Populus and Ben Lomond substations and was completed in November 2010.

Project Timeline

  • Informational meetings – October 2007 - October 2008
  • Permitting and obtaining rights of way – December 2007 - April 2009
  • Construction – February 2009 - December 2010
  • Ben Lomond to Terminal section in service to customers - March 2010
  • Completion of Populus - Terminal project – November 2010

Additional Information About the Project

Throughout all phases of this project, we worked carefully to minimize impacts to the community and the environment. This continues to be our priority during ongoing maintenance activities.

Check these links for additional information, including the current Populus to Terminal map (PDF), newsletter and photos (image 1, image 2, image 3 (PDF)).

To contact us about this project, please call us at 801-220-4221 or e-mail Please be sure to include the project name, “Populus to Terminal project,” in your inquiry.


(Updated December 15, 2016)