[1] 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.

John Lowery Brown, who kept a diary of the party's journey from Georgia to California, wrote on that day: "Lay bye.

Members of this party founded Auraria (later absorbed into Denver City) in 1858 and touched off the gold rush to the Rockies.

The plains counties of Adams, Arapahoe, Douglas, Denver, Elbert and Jefferson are each credited with having produced small amounts of gold.

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.

Hill's smelter could recover gold from the sulfide ores, an achievement that saved hardrock mining in the district.

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.

Other vein discoveries included Ontario, Key West, Boss, Fountain, and Gold Flake.

Gold in some upper gravel benches north of the Blue River was recovered by hydraulic mining.

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.

[9]Before any prospectors in Park County began excavating the mountains, they used placer mining to extract gold from the local waterways.

[10] The mining town of Montgomery in Hoosier Pass had another small placer gold operation in 1911.

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.

In the first two years, the mine produced $300,000 worth of ore.[13] Once the gold had dried up in Buckskin Gulch, they moved on to quartz.

[14] Off Mosquito Gulch, the London Lode Mine produced gold, silver, and copper.

[15] 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.

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.[2]: 60–61  The Leadville district produced 3,200,000 troy ounces (100 t) of gold, mostly as a byproduct of silver mining.

By 1880, the Little Annie vein helped make Summitville Colorado's largest gold producer.

However, Galactic Resources declared bankruptcy in December 1992, and the US Environmental Protection Agency stepped in to prevent releases of pollution from the property.

[23] The Sneffels-Red Mountain-Telluride district, in San Miguel and Ouray counties at the southwest end of the Colorado Mineral Belt, was discovered in 1875.

[19] "Part-time cowboy and full-time drinker" Robert Womack found gold float in 1879, which led him to digging countless prospecting holes in an attempt to find its lode, earning him the name "Crazy Bob".

The towns of Cripple Creek and Victor were established to serve the mines and miners of the district.

[26][27] The Cripple Creek mining district covers a Miocene volcanic caldera filled with quartz latite porphyry.

From 1976 to 1989, the company produced 150,000 troy ounces (4.7 t) of gold by reprocessing tailings and mining two small surface deposits.

[29][30] Some miners who worked in this district died in different ways including flu, pneumonia, in the mine, at home, or suicide.