The agency is hosting open houses in six Utah cities next month, starting Aug. 20 in Nephi, and accepting public comment until Sept. 30.
Utah is bracing for expansion of its electrical grid because it sits between new power-generation projects to the northeast and major markets to the southwest.
"There have been no transmission upgrades since the 1970s, which is why you are seeing so many proposals at this time," said Beverly Gorny, a spokeswoman with Wyoming BLM. "The interconnection system is at capacity. There is an interest in renewable energy but nowhere for that energy to travel."
The agency also anticipates initiating an environmental review soon of the Zephyr transmission line, the other proposed project to move Wyoming power across Utah.
A draft EIS for Gateway South is due at the beginning of next year. This line would move up to 1,500 megawatts more than 400 miles from the planned Aeolus Substation in south central Wyoming to the planned Clover Substation near Mona. As opposed to the direct-current TransWest Express, Gateway South is an alternating-current project that could off-ramp power along its route through Colorado and Utah.
BLM is considering where to grant the necessary 250-foot-wide right of way, which would feature four or five self-supporting steel lattice tower structures, between 140 and 190 feet high, every mile.
Gateway South is part of larger plans by PacifiCorp, Rocky Mountain Power's parent, to expand transmission capacity.
BLM hopes to keep new transmission lines inside West-wide Energy Corridor, which the federal government adopted in 2009 after years of planning, study and litigation. It also is trying to keep lines out of military training areas, as well as sage grouse habitat, Forest Service roadless areas and other environmentally sensitive places, according to Gorny.