The West Flank FORGE team proposed an R&D plan that aimed to effectively reduce risks to industry and enable development of the enormous EGS resource potential. The team is worked in partnership with the U.S. Department of Defense to reduce our Nation’s dependency on fossil fuels and to safeguard the military readiness for the United States. Drilling in and around the selected FORGE location had indicated remarkably low permeability and very attractive temperatures - key elements for an EGS test site. The West Flank FORGE team was led by Sandia National Laboratories and includes members from: Lawrence Berkeley National Laboratory, U.S. Navy & the U.S. Navy Geothermal Program Office, Coso Operating Company, U.S. Geological Survey (Menlo Park, California), University of Nevada, Reno (UNR), GeothermEx / Schlumberger, and Itasca Consulting Group, Inc.


The West Flank FORGE team's proposed candidate site did not proceed to Phase 2. To learn more about their findings you can review the West Flank FORGE team's Phase 1 Report and data submissions on the Geothermal Data Repository.   


The proposed West Flank FORGE site is located within the U.S. Navy’s China Lake Naval Air Weapons Station (NAWS). The project area is approximately 35 miles (55 km) North of Ridgecrest, California, just east of the Sierra Nevada, in the western portion of the Coso volcanic field.  

Technical Information

The presence of an available deep well that demonstrates EGS conditions, information from numerous other wells within and adjacent to the proposed site, and the shallow granitic basement demonstrate the attractiveness of this candidate FORGE location. Temperature logs in the deep well and other nearby wells have enabled the West Flank FORGE team to determine that the minimum and maximum temperature range required for FORGE will be encountered between the depths of .93 to 1.2 mi (1.5 to 2.5 km), respectively, confirming that the site fits the required depth and temperature ranges. The site is equipped with 13 nearby borehole seismometers that can be used for tomographic experiments and for monitoring EGS operations. Other geophysical data sets are also available. This combination of attributes motivated the West Flank FORGE team to propose the site.

Fun Facts
  • Geothermal exploration activities at Coso began in the 1960s.
  • NAWS encompasses over 1.1 million acres making it one of the largest military bases in the country. Civilians comprise about 90% of the base personnel.
  • The U.S. Navy Geothermal Program Office has significant geoscientific experience at Coso. 

Additional information on the West Flank FORGE team is available at