Leadville
[Placer] gold was discovered in 1859 in California Gulch, about seven miles north of the present town of Leadville. The rush that followed was short but sweet; the camp was called Oro—gold! About $5,000,000 was produced from the placer mines within two years, though by 1861 the area was all but deserted, for the easily won placer gold was gone.
Early-day Leadville sprawled among its mine dumps at an elevation of 10,200 feet. The Sawatch Range, in the background, contained many smaller mining communities, now deserted. Mt. Massive, the state’s second highest peak, forms the crest of the continental divide here. (State Historical Society of Colorado photo)
In 1875 a smelter was erected a few miles downstream from Oro to process cerussite—silver-rich lead carbonate—that occurred in the [placer] sands. For years this mineral had been considered a nuisance because, being much heavier than sand, it tended to separate out with the gold. The new town of Leadville sprang up near the smelter and shortly afterward more [lode] deposits were discovered south of the placer workings. From $63,000 in 1875, production climbed to $2,500,000 in 1878 and more than $15,000,000 in the peak year of 1882.
Geologically, the ores of this district occur as Tertiary replacements and [veins] in Ordovician, Devonian, and Mississippian limestones. The “Blue” or Leadville Limestone, of Mississippian age, contains the richest ore. Ore deposits were formed after the limestones had been faulted and cracked extensively by mountain-building movements; the ores themselves probably crystallized from molten or gaseous materials involved in related igneous intrusions. River gravels and glacial debris mask the true nature of the [lode] deposits, but studies in the mines show that the [fault] systems along which ores are deposited trend north or north-northeast.
The Leadville district is now experiencing its third mining boom as a newly recognized lead-zinc orebody is being developed. Production is expected to reach 700 tons of ore per day by 1971. Total production of gold, silver, lead, zinc, and copper in the district has reached $500,000,000.