Geothermal energy is heat from the earth that can be used to generate electricity. The Department of the Interior's Bureau of Land Management (BLM) has the primary responsibility for leasing public lands to private companies for geothermal development. In addition, the Secretary of each military department has the authority to develop geothermal resources on military lands and to keep the proceeds from the sale of electricity generated from those resources for use by the Department of Defense. The Navy's Geothermal Program Office, located at the China Lake Naval Air Weapons Station in California, manages and develops geothermal resources for the military. Currently, two geothermal power plants at China Lake are the only ones on military lands. A private company, which built, owns, and operates the power plants at China Lake, sells the electricity to a utility company and pays the Navy royalties on these sales as well as other types of compensation. GAO was asked to provide information on (1) the Navy's annual revenues from the geothermal facility at China Lake, (2) how the Navy uses the revenues it collects from the geothermal facility, (3) the budget oversight the Navy provides programs funded from geothermal revenues, and (4) how the Navy's geothermal program differs from BLM's program.