Between 1993 and 1995, Placer Dome, unsuccessfully carried out exploration, including 6 RC and 2 diamond core holes totaling 1,542m, looking for the disseminated gold mineralization in an area south of Andacollo, La Primavera, where significant placer workings exist. From 1996 through to 1998, Cameco Argentina continued exploration in the area including 2,890 m of additional drilling. In 1998, the Andacollo mineral deposits were expropriated by Corporación Minera del Neuquén, Sociedad del Estado Provincial (CORMINE SEP) the mining agency of the provincial government. CORMINE then granted a 20-year usufruct contract to Minera Andacollo Gold SA (MAGSA), which initiated an exploration program within the central part of the district around Cerro Minas. In 2001, MAGSA received approval by the Neuquén government to begin mining activity and initiated production in 2003, mainly from the Buena Vista, San Pedro Sur, Sofía-Julia and Erika mines.