Announced by interior secretary Sally Jewell, the project is part of a strategy to improve the grid and spur the development of renewable energy.
The Gateway West transmission line will provide up to 1.5GW of capacity from southern Wyoming to southern Idaho. It is being built by utilities Idaho Power and Rocky Mountain Power.
While Wyoming has very little installed wind capacity, the 2020 wind energy pipeline for the state is calculated by Windpower Intelligence to be 6,975MW, the second highest of any US state, after Texas.
However, Wyoming is the least populous state in the country, meaning the power needs to be shifted to more densely populated regions.
"The line will strengthen the Western grid, bringing a diversified portfolio of renewable and conventional energy to meet the region's projected growth in electricity demand," said Jewell.
"When built, these projects will help increase electric reliability, integrate new renewable energy into the grid, and save consumers money," she added.
Idaho Power and Rocky Mountain Power proposed the line as ten segments originating at the Windstar substation near Glenrock, Wyoming, and ending at the Hemingway substation near Melba, Idaho.
Eight of the ten stretches have been approved, with the last two going through the final stages of approval.