BOISE, IDAHO--(Marketwired - Sept. 18, 2013) - U.S. Geothermal Inc., (NYSE MKT:HTM)(TSX:GTH) a leading renewable energy company focused on the development, production, and sale of electricity from geothermal energy, announced today that the Guatemalan Ministry of the Environment and Natural Resources ("MARN") has issued an Environmental License for the construction and operation of the planned, first phase, 25 megawatt power plant at the El Ceibillo site.

The El Ceibillo development project is an advanced stage, steam geothermal prospect within a 24,710 acre (100sq km) energy rights concession located 8.5 miles (14 km) from Guatemala City, the largest city in Central America.

Temperatures in excess of 500° F (275° C) have been encountered during recent drilling at this project.

The license is based on the Environmental Impact Assessment Study that was submitted in December 2012, describing the initial design of the 25 megawatt facility, and requires the submittal of final design specifications for review by MARN prior to starting physical construction of the plant. Additionally, the license requires compliance with all legal and regulatory requirements under Guatemalan law, submittal of an air quality monitoring plan, and that final design comply with the strict guidelines for noise, dust and hydrogen sulfide emissions. Prior to issuance of the license, an environmental bond of $344,850 Quetzals (approximately US $45,000) was posted with the Ministry of Environment and Natural Resources.

"The issuance of this license is an important step in our development plans for the El Ceibillo Project," said Dennis Gilles, CEO of US Geothermal. "While we are still working on developing the geothermal reservoir, having the environmental license in hand will allow us to move the project forward within an efficient timeframe."

Please visit our Website at: www.usgeothermal.com

About U.S. Geothermal Inc.:

U.S. Geothermal Inc. is a leading renewable energy company focused on the development, production and sale of electricity from geothermal energy and is operating geothermal power projects at Neal Hot Springs, Oregon, Raft River, Idaho, and San Emidio, Nevada. The company is also developing a second phase expansion project adjacent to our Phase 1 San Emidio power plant, in addition to the El Ceibillo development project in Guatemala.

The information provided in this news release may contain forward-looking statements within the definition of the Safe Harbor provisions of the US Private Securities Litigation Reform Act of 1995. These statements are based on U.S. Geothermal Inc.'s current expectations and beliefs and are subject to a number of risks and uncertainties that can cause actual results to differ materially from those described, including but not limited to, the results from the exploration, production and injection well drilling at El Ceibillo. Readers are cautioned to review the risk factors identified by the company in its filings with Canadian and US securities agencies. Forward-looking statements are based on management's expectations, beliefs and opinions on the date the statements are made. U.S. Geothermal Inc. assumes no obligation to update forward-looking statements if management's expectations, beliefs, or opinions, or other factors, should change.

The NYSE MKT and the TSX do not accept responsibility for the adequacy of this release.