Project Overview


  • FERC P-13642
  • Estimated Average Annual Energy: 1300 GWh
  • Estimated Installed Capacity: 400 MW
  • Number of Proposed Turbine Generators: 3
  • Reservoirs sized at approximately 4,000 acre-feet
  • Head (Height Between Reservoirs) 1,025 feet

Montana based, Absaroka Energy, LLC is developing the Gordon Butte Pumped Storage Hydro Project. The project will be located on private land in Meagher County, Montana, three miles west of the small town of Martinsdale. Our project is designed to take advantage of the unique geological features of Gordon Butte to create a new closed-loop pumped storage hydro facility. This facility will provide ancillary and balancing capabilities to Montana’s emerging renewable energy industry, as well as, provide multiple services to facilitate stability, reliability, growth and longevity to existing energy infrastructure and resources in the state and region.

The Gordon Butte Hydro Pumped Storage Facility will consist of upper and lower closed-loop reservoirs connected by an underground concrete and steel-lined hydraulic shaft. Our pumped storage hydro project will be an off-stream facility, constructed out of any existing watersheds thereby minimizing impacts to the local watersheds and riparian ecosystems. Each reservoir will be approximately 4,000 feet long and 1,000 feet wide with depths of 50 to 75 feet. As currently designed, an underground powerhouse with three turbine-generators would be located at the bottom reservoir. These generators would provide an installed capacity of 400 megawatts, allowing for an estimated annual energy generation of 1300 gigawatt hours.

GB Energy Park received its preliminary permit from the Federal Energy Regulatory Commission in 2013. This was followed by a multi-year consultation process with state and federal agencies, local landowners, environmental groups, and other interested stakeholders to identify, study and mitigate important issues related to the construction of this project. October 1, 2015, GB Energy Park filed the Final License Application for the project with FERC. The Commission accepted the license application as complete on November 16, 2015 and issued its Environmental Analysis with a Finding of No Significant Impacts on September 27, 2016.

On December 14, 2016, GBEP received an Original License for the Gordon Butte Pumped Storage Hydro Project. The license authorizes GBEP to construct and operate the facility for a period of 50 years.