The Mercedes Property consists of approximately 69,000 hectares of mineral concessions under lease from the government of Mexico. The area is covered by 39 mineral concessions, all of which have been titled as Mining Concessions, according to Mexican mining law. The titles are valid for 50 years from the date titled. All of the concessions are in good standing with mining law obligations through twice-annual tax payments and required assessment work.
Exploration and development work on the property was conducted in at least two or three distinct periods. The Mercedes, Tucabe, Saucito, Anita, Klondike, Rey de Oro, Reina, and Ponchena veins were the focus of exploration and development work on a limited to moderate scale during the late 19th century and early 20th century.
The Tucabe vein was mined around the turn of the century. A cyanide mill was constructed on the site and the Tucabe vein was accessed through a series of tunnels and shafts, covering over 600 m of strike and a vertical range of over 150 m. The Mercedes vein was discovered in 1936. Anaconda Copper Company optioned the property in 1937 and spent two years exploring underground. The work included sinking a 50 m shaft and excavating a series of tunnels and internal raises for sampling and reserve estimation.
An exploration program conducted in 2005 resulted in the discovery of the bonanza grade Corona de Oro shoot in the Mercedes vein. Drilling expanded in 2006-2007, focusing on the Mercedes, Klondike, and Lupita veins.