El Gallo is a 3,000 tpd open-pit gold/silver mine located in the foothills of the Sierra Madre Mountain Range in Mexico’s Sinaloa State. Gold is recovered through heap leaching and adsorption/desorption/recovery (ADR). Production commenced at El Gallo with the first gold pour in September 2012. Tierra Group’s design team designed a heap leach pad expansion during the first half of 2012 as part of the re-commissioning of the El Gallo project. In addition, Tierra Group developed construction documents (drawings and construction specifications) and provided engineering support during construction.