According to published historic records, Minera Industrias Peñoles was incorporated in 1887 to operate the Jesus Maria and San Rafael silver mines and took its name from the local community of Peñoles. The full extent of the historic mine workings is unknown, but mining appears to have been selective and limited to within approximately 100 metres from the surface.
The only modern exploration work that was completed on the property prior to 2011 consisted of a four-hole drill program completed by Aurcana Corporation (“Aurcana”) in 2004, and surface mapping, sampling, a limited IP survey, and a five-hole drill program completed by Riverside in 2008 and 2009.
The drill holes completed by Aurcana and Riverside returned encouraging results and showed that El Capitan had potential to host a bulk-tonnage, low-grade gold deposit. Preliminary metallurgical tests completed by Sierra Madre in 2011 using Riverside drill core indicated that the gold mineralization at El Capitan could likely be recovered using cyanide leaching.
Since March 2011, exploration work and drilling funded by Riverside’s partner has primarily focused on the Jesus Maria Silver Zone and the El Capitan Gold Zone.