gateway west

The legislation means that about 300 miles of transmission lines will cross over what used to be designated national conservation area.

Rocky Mountain Power's energy-generating capacity is about 55 percent coal, 25 percent natural gas, 10 percent hydroelectric, and 10 percent wind.

The plan, totaling some $3.5 billion, will involve significant upgrades to existing wind plants, construction of a 140 miles of transmission line in Wyoming and adding up to 1,100 megawatts of new wind projects -- primarily in Wyoming -- by the end of 2020.

Federal officials have already approved the rest of the project, but no work has started.