The Rosario Gold Project is centered on the historical town of Rosario, sixty-four kilometers (39 mi) southeast of Mazatlan.  According to the local legend that describes how the first mine was established in 1655, ranch foreman Bonifacio Rojas went looking for a lost cow. At a spot now known as Santiago Hill, his rosary broke and fell to the ground, beads scattering. Throwing his hat down to mark the spot, he continued on horseback searching for the bovine in question. As night fell he still hadn’t found the cow, and decided to camp on the spot where he’d thrown his hat. In the morning he found a large vein of silver under his smoldering campfire. 

Silver and gold deposits in what is described as mesothermal veins were mined by the Spanish and then Mexican companies and later by Americans out of California. The mine ran into financial woes which lead to technical difficulties and the closing was consummated by a typhoon which flooded the mine and shut it down in and around the time of the Mexican Revolution and has not been opened since. Production records are not well documented however, its estimated that 300 million ounces of silver and several million ounces of gold were produced from this mine.

Oro Gold is one of the first modern exploration companies to explore within the belt looking for similar deposits. The company has a number of projects which have identified both bulk-tonnage and high grade systems within the belt. Exploration to date has a number of surveys and diamond drilling on several different target areas.