The Mystic Lake Hydroelectric Project is located on West Rosebud Creek, in Stillwater and Carbon counties about 75 miles southwest of Billings, in southern Montana. The project began operation in 1925 and received its last operating license in 2007 and became the first project to do so using the Federal Energy Regulatory Commission’s Integrated Licensing Process (ILP.)
PPL Montana operates the project in both base load and peaking modes depending on water availability, electric demands, and license constraints. In general, Mystic Lake is used to store water during heavy runoff months May through July, and then is used to augment flows during the rest of the year. [FERC]
The East and the West forks of the Rosebud Creek, which together flow into the Stillwater River, are very popular for fishing, especially for small cutthroat trout, brook trout and rainbow trout in its upper, mountainous sections. Depending on the flows, these ‘creeks’ provide great whitewater boating opportunities, often Class II-IV in some sections.