Great Basin Transmission, LLC (St. Louis, Missouri, U.S.) held an open season in November 2008 to receive proposals for the purchase of long-term point-to-point transmission rights on the Southwest Intertie Project. Successful bidders in the open season will secure firm transmission rights to support financing of new generation resources and to allow existing generation resources to transport their output to attractive liquid markets in the western United States.

Southwest Intertie Project is a proposed aboveground 500-kVac transmission line stretching more than 500 miles (805 km) between southern Idaho and southern Nevada. As much as 1850 MW of north-to-south transmission capacity and 1850 MW of south-to-north transmission capacity will be available for purchase during the open season.

Southwest Intertie Project will provide a new energy pathway connecting the existing high-voltage transmission infrastructure near Twin Falls, Idaho, and the existing systems in northern Nevada and the Las Vegas, Nevada, area. It will provide direct interconnection and viable access to multiple transmission providers in the West, which may include Arizona Public Service, Idaho Power, Los Angeles Department of Water and Power, Nevada Power, PacifiCorp, Salt River Project, Sierra Pacific Power, Southern California Edison and Western Area Power Administration.

Southwest Intertie Project is being developed in phases. The first phase, connecting southern Nevada with northern Nevada, is expected to begin construction in 2009 and achieve commercial operation as early as 2010.