Cerro Gordo The “fat hill” produced silver, lead, and zinc for a century. At its peak, over 1,000 people lived here working in mines as the San Felipe and Union. At the time the smelters were the best there were. Silver was roasted and formed into bullion, sent down the Yellow Grade road by mule team, then shipped across Owens Lake by steamboat. From the lakeside port of Cartago, the bullion was loaded onto Remi Nadeau‘s freighters and hauled into Los Angeles.