In many Colorado mining districts the easily discovered and worked placers were the first big strikes of a typical gold rush. But the free gold supply in stream beds quickly became depleted, and the initial phase was followed by prospecting for veins of lode gold that were the original source of the placer gold. The hills above Granite are pockmarked with numerous old mining tunnels from hard rock mining, evidence of the typical second stage of a gold rush cycle. Their neighbors in Leadville went on to discover silver, resulting in a silver rush, but Granite never got that far. In just a few years their ore began to play out, and the town's population, once as high as 7000, began to decline.