Gold mining in Colorado, a state of the United States, has been an industry since 1858. It also played a key role in the establishment of the state of Colorado.
Explorer Zebulon Pike heard a report of gold in South Park, present-day Park County, Colorado, in 1807.A. H. Koschman and M. H. Bergendahl (1968) Principal gold-Producing Districts of the United States, US Geological Survey, Professional Paper 610, p.143.
Gold discoveries in Colorado began around Denver; prospectors traced the placer gold to its source in the mountains west of Denver, then followed the Colorado Mineral Belt in a southwest direction across the state to its terminus in the San Juan Mountains. The Cripple Creek district, far from the mineral belt, was one of the last gold districts to be discovered and is still in production.
Denver-area placers
On June 22, 1850, a wagon train bound for California crossed the South Platte River just north of the confluence with Clear Creek and followed Clear Creek west for . Lewis Ralston dipped his gold pan into a stream flowing into Clear Creek and found about a quarter of a troy ounce worth almost $5 at the time in his first pan. John Lowery Brown, who kept a diary of the party's journey from Georgia to California, wrote on that day: "Lay bye. Gold found." In a notation above the entry, he wrote, "We called this Ralston's Creek because a man of that name found gold here." Ralston continued to California, but returned to 'Ralston's Creek' with the Green Russell party eight years later. Members of this party founded Auraria (later absorbed into Denver City) in 1858 and touched off the gold rush to the Rockies. The confluence of Clear Creek and Ralston Creek, the site of Colorado's first gold discovery, is now in Arvada, Colorado.Voynick, S.M., 1992, Colorado Gold, Missoula: Mountain Press Publishing Company,
A gold discovery in 1858 in the vicinity of present-day Denver sparked the Pike's Peak Gold Rush. In 1858, prospectors focused on the placers east of the mountains in the sands of Cherry Creek, Clear Creek, and the South Platte River. However, the placer deposits on the plains were small, and when the first rich discoveries were made in early 1859 in the mountains farther west, the miners abandoned the placers around Denver.
Although the economic portions of the gold placers around Denver were quickly exhausted, producers of construction aggregate in the area sometimes recover small amounts of gold from their sand and gravel washing. The plains counties of Adams, Arapahoe, Douglas, Denver, Elbert and Jefferson are each credited with having produced small amounts of gold.Ben H. Parker Jr., Gold placers of Colorado, book 1, Quarterly of the Colorado School of Mines, v.69, n.3, July 1974, p.26.
Central City-Idaho Springs district
On January 5, 1859, during the Pike's Peak Gold Rush, prospector George A. Jackson discovered placer gold at the present site of Idaho Springs, where Chicago Creek empties into Clear Creek. It was the first substantial gold discovery in Colorado. Jackson, a Missouri native with experience in the California gold fields, was drawn to the area by clouds of steam rising from some nearby hot springs. Jackson kept his find secret for several months, but after he paid for some supplies with gold dust, others rushed to Jackson's diggings. The settlement was later renamed Idaho Springs, after the hot springs.Robert L. Brown (1985) The Great Pikes Peak Gold Rush, Caldwell, Ida.: Caxton, p.26-32.
In May 1859, John H. Gregory found a gold-bearing vein (the Gregory Lode) in Gregory Gulch between Black Hawk and Central City. Within two months, many other veins were discovered, including the Bates, Gunnell, Kansas, and Burroughs.Paul K. Sims and others (1963) Economic Geology of the Central City District, Gilpin County, Colorado, US Geological Survey, Professional Paper 359, p.7-8. Other early mining towns in the district included Nevadaville and Russell Gulch.
Hardrock mining boomed for a few years, but then declined in the mid-1860s as the miners exhausted the shallow parts of the veins that contained free gold and found that their amalgamation mills could not recover gold from the deeper sulfide ores.A. H. Koschman and M. H. Bergendahl (1968) Principal Gold-Producing Districts of the United States, US Geological Survey, Professional Paper 610, p.86.
Nathaniel P. Hill built Colorado's first successful ore smelter in Blackhawk in 1868. Hill's smelter could recover gold from the sulfide ores, an achievement that saved hardrock mining in the district. Other smelters were built nearby. Through 1959, the district produced about , mostly from sulfide veins in gneiss and granodiorite.
The early gold discoveries were at the northeast end of the Colorado Mineral Belt, a large alignment of mineral deposits that stretches northeast-southwest across the mountainous part of Colorado. From Idaho Springs, prospectors followed the Colorado Mineral Belt west along Clear Creek, then over the mountain passes to South Park and to the headwaters of the Blue River.
Breckenridge district
Placer gold was discovered in the Breckenridge, or Blue River district, in 1859 at Gold Run by the Weaver Brothers, at Georgia, American, French, and Humbug Gulches on the Swan River, on the Blue River itself, and at the confluence of French Gulch and the Blue River.
Harry Farncomb found the source of the French Gulch placer gold on Farncomb Hill in 1878. His strike, Wire Patch, consisted of alluvial gold in wire, leaf and crystalline forms. By 1880, he owned the hill. Farncomb later discovered a gold vein, which became the Wire Patch Mine. Other vein discoveries included Ontario, Key West, Boss, Fountain, and Gold Flake.
Lode deposits were developed in the 1880s, as prospectors followed the gold to its source veins in the hills. Gold in some upper gravel benches north of the Blue River was recovered by hydraulic mining. Gold production decreased in the late 1800s, but revived in 1908 by gold dredging operations along the Blue River and Swan River. The Breckenridge mining district is credited with production of about of gold.A. H. Koschman and M. H. Bergendahl (1968) Principal Gold-Producing Districts of the United States. US Geological Survey, Professional Paper 610, p.116-117.
The gold mines around Breckenridge are all shut down, although some are open to tourist visits. The characteristic gravel ridges left by the gold dredges can still be seen along the Blue River and Snake River, and the remains of a dredge are still afloat in a pond off the Swan River.
South Park districts
Prospectors discovered rich placer deposits on the west side of South Park in 1859. The deposits were in valleys on the east side of the Mosquito Range. The town of Alma, Colorado, the heart of this district, was established on December 2, 1872 by miners working the area, though that area had been actively mined since 1860. The principal districts were the Alma-Fairplay district on the headwaters of the South Platte River, and the Tarryall district along Tarryall Creek northwest of Como, Colorado. Important lode gold deposits were later discovered above Alma. A floating dredge worked the floor of the South Park valley east of Fairplay from 1941 to 1952, leaving the distinctive gravel ridges that can still be seen. Production from the Tarryall district was , almost all from placers. The Alma-Fairplay district produced , more than two-thirds of which came from lode deposits.A. H. Koschman and M. H. Bergendahl (1968) Principal Gold-Producing Districts of the United States, US Geological Survey, Professional Paper 610, p.109-110. Before any prospectors in Park County began excavating the mountains, they used placer mining to extract gold from the local waterways. Placer mines began to appear all over Park County after 1861. Placer gold was found in Tarryall, Fairplay, Alma, Breckenridge, and Leadville. A notable amount came from the beds of the South Platte River. Many placer claims existed to the south and west of Alma. The mining town of Montgomery in Hoosier Pass had another small placer gold operation in 1911. Two notable placer mines in the Alma mining district are Snowstorm, home of the famous Snowstorm Dredge, and Cincinnati. In 1882, the Alma Placer Mining Company owned roughly 640 acres of placer mines. The only hindrance is that this type of mining can only be conducted during the short summer months.
After prospectors established placer mines all over Park County's gulches, they moved on to the more difficult mountain veins to plunge the depths for riches. Lode mining costs more than surface mining, and there are also significant risks to this method including a loss of air supply, explosions, and implosions.Columbia University and Paul Lagasse, “Mining,” in The Columbia Encyclopedia, 8th ed. (New York, NY: Columbia University Press, 2018). Like everyone who came West had hoped, gold was found in the lode mines. The first lode mine in the Alma district was located in Buckskin Gulch, and it was explored by local icon Joseph Higginbottoms, aka Buckskin Joe.Horace B. Patton, Arthur J. Hoskin, and Gurdon M. Butler, Geology and Ore Deposits of the Alma District, Park County, Colorado (Denver, Colorado: The Smith-Brooks printing, 1912), 149. That first claim was called the Phillips Lode Mine. In the first two years, the mine produced $300,000 worth of ore. Once the gold had dried up in Buckskin Gulch, they moved on to quartz.
Paris Mine, also located off Buckskin Gulch, is another lode mine producing oxidized gold.Patton, Hoskin, and Butler, Geology, 174. Off Mosquito Gulch, the London Lode Mine produced gold, silver, and copper. Magnolia Mine in Montgomery was well known for producing gold, lead, silver, and copper, but it also produced quartz, pyrite, and limonite.
Leadville district
The history of the Leadville district began in April 1860, with one of the richest discoveries of Colorado placer gold at California Gulch, the site of Oro City.Ben H. Parker Jr., Gold Placers of Colorado, Book 2, Colorado School of Mines Quarterly, Oct. 1974, v.69 n.4 p.17. Another rich discovery was made at McNulty Gulch along the headwaters of Tenmile Creek. The placers were exhausted within four years, but lode gold was discovered in 1868. The gold discoveries led to the discovery of the silver deposits in 1877, and the founding of the city of Leadville. The Little Johnny silver and lead mine, dating from 1879, was further developed in 1893, by John F. Campion and James Joseph Brown, which resulted in the production of large deposits of high-grade gold-copper ore. The Leadville district produced of gold, mostly as a byproduct of silver mining.Mark W. Davis and Randall K. Streufert (1990) Gold Occurrences of Colorado, Colorado Geological Survey, Resource Series 28, p.54-55.
Summitville district Prospectors found placer gold in 1870 in the Wrightman Fork of the Alamosa River. Gold veins were discovered in 1871, and large-scale production started in 1875 after the construction of a mill. By 1880, the Little Annie vein helped make Summitville Colorado's largest gold producer. Over 100,000 ounces of gold were produced by 1890. Operations were continuous until 1906, then sporadic after that.Bruce Geller, Summitville, Colorado, Mining Record, 25 Feb. 1987, p.17. Gold production up to 1990 was .Mark W. Davis and Randall K. Streufert, 1990, Gold Occurrences of Colorado, Colorado Geological Survey, Resource Series 28, p.28.