A recent presentation by the Northwest Power and Conservation Council indicates that Montana's wind resources may be consistently more productive than the Columbia River Gorge. But while wind facilities along the Columbia River generate 5,700 megawatts, Montana generates only 700. The presenter, John Fazio, is a senior systems analyst for the NWPCC. A summary of the report is available on the NWPCC website.
In winter, electricity use peaks in the Pacific Northwest during the late morning and early evening hours. Preliminary analysis shows that Montana wind generation is a much better match with the larger region's winter peak demand than Columbia Gorge wind generation. Analysts with NWPCC compared wind generation at Montana's Judith Gap with generation in the Gorge and found the Montana facility will usually generate more electricity.
One problem for Montana wind generation is its proximity to load centers in the Pacific Northwest. The Columbia Gorge is close to the high capacity transmission lines built for the Columbia River's hydroelectric dams. These existing lines had available capacity, which enabled rapid expansion of facilities in the Gorge over the past decade. Montana has several transmission lines going west to Spokane, Seattle, Boise, and Portland. However, these lines are currently largely reserved for other power sources, according to the report.
The Wind Energy in Montana website offers more information.