Colorado has been a major gold producing state since the 1860’s and much of the state’s early economic growth depended on the mining of gold. The initial gold discovery occurred in 1859 in Cherry Creek near the confluence with the South Platte River. Since that first placer gold discovery, the estimated total gold production for the state has exceeded 42,000,000 troy ounces (1.3 million kg) [Ed: as of original publication in 1990. Only one Colorado mine continues to produce gold, the Cripple Creek & Victor Gold Mine at Victor, an open-pit heap leach operation owned by Newmont Mining Corporation, which produced 211,000 troy ounces (6,600 kg) of gold in 2014].
The majority of Colorado gold deposits occur in a northeast trending zone called the Colorado Mineral Belt (also known as the COMB). The COMB, which extends from the Jamestown District in Boulder County on the northeast to the La Plata Mountains on the southwest, crosses a variety of geologic environments and includes deposits of important metallic minerals as well as gold occurrences. This belt of mineral deposits coincides with a large number of Laramide-to-Tertiary igneous rocks which occur in a belt of similar areal extent to the COMB. Not all of the state’s gold deposits are part of the COMB, however. The most productive gold camp to date in Colorado, the Cripple Creek district which includes Victor, is located east of the COMB.
This popular volume discusses the classification of all the important gold occurrences and gold districts across the state by age. It was initially prepared to meet the needs of industry and the public in general, especially since many valuable references concerning gold in Colorado were out of print. It identifies much of this hard-to-find information and will aid in the continued study of Colorado’s gold deposits. The publication includes a table of occurrences showing map number, type, location, ore/mineral, host, control, and an extensive bibliography of references. It also includes two plates: Plate 1 Gold Districts and Placers, and Plate 2 Late Cenozoic, Middle Tertiary, and Laramide Igneous Rocks and Tectonic Elements. RS-28