The Leadville mining district, located in the Colorado Mineral Belt, was the most productive silver-mining district in the state of Colorado and hosts one of the largest lead-zinc-silver deposits in the world. Oro City, an early Colorado gold placer mining town located about a mile east of Leadville in California Gulch, was the location to one of the richest placer gold strikes in Colorado, with estimated gold production of 120,000–150,000 ozt (8,200–10,300 lb; 3,700–4,700 kg), worth $2.5 to $3 million at the then-price of $20.67 per troy ounce.
Cumulative production through 1963 was 240 million troy ounces (16 million pounds; 7.5 million kilograms) of silver, three million troy ounces (210 thousand pounds; 93 thousand kilograms) of gold, 987 million tonnes (2.2 trillion pounds; 987 billion kilograms) of lead, 712 million tonnes (1.6 trillion pounds; 712 billion kilograms) of zinc, and 48 million tonnes (110 billion pounds; 48 billion kilograms) of copper. The district also produced byproduct bismuth, and iron-manganese ore.
