Park County is in the mountainous central part of Colorado and includes a central broad basin, called South Park, rimmed on the east and north by the Front Range, on the west by the Mosquito Range and on the south by an unnamed range of low hills. Gold is the principle mineral in the county which ranks eighth in the State in gold production. Through 1959 about 1,364,430 ounces of gold has been produced.
Placer gold was discovered in Park County in 1859; this was one of the earliest mineral discoveries in Colorado. Prospectors, some arriving by way of the Arkansas River and others arriving by way of the South Platte River, found gold in the streams of South Park and later rich lodes at the headwaters of the South Platte and its tributaries. Nearly all the lode gold has come from the Alma district, and the placer gold has come from the Fairplay, Tarryall, and the Alma districts.
The Alma district lies east of the Leadville district along the east slope of the Mosquito Range and includes the Mosquito-Buckskin, Montgomery, Horseshoe, and Alma placers. The earliest discoveries in the Alma district appear to have been of lode deposits along the headwaters of Buckskin Gulch and the South Platte River (Henderson, 1926, p. 36-38). The Phillips lode in Buckskin Gulch was discovered in 1860, and other lodes were discovered in rapid succession soon after. The gold obtained from the lodes from 1860 to 1867 was worth about $710,000 (Henderson, 1926, p. 37, 196). After the easily disintegrated and oxidized ores near the surface were exhausted, the mines were closed because the sulfide ores at depth could not be successfully treated by amalgamation. In the summer of 1871, silver ore was discovered on Mount Lincoln and Mount Bross, and mining activity in the district increased. Silver was the chief metal mined through 1885, and high silver production was maintained until 1892 when the price of silver began to drop. In later years production of silver fluctuated considerably. In 1873, outcrops of the London vein were discovered (Singewald and Butler, 1941, p. 36), but the London mine was not located and opened until 1875. It became the largest producer in the district and, though production fluctuated, it operated almost continuously until 1942.
Gold production from the Fairplay (Beaver Creek) district was entirely from placer deposits and included production from the Snowstorm and Fairplay placers along the South Platte River and small placers along Sacramento and Beaver Creeks. Gold placers were discovered in the district about 1859, and through 1872 their output was valued at about $1 million (48,380 ounces) (Henderson, 1926, p. 36-38). From 1872 through 1938 the placers were worked sporadically without any spectacular results. From 1939 to 1951, the district was rejuvenated and about 125,000 ounces of gold was produced. These operations were terminated in 1952, and the district was virtually idle from 1952 through 1959. The minimum total gold yield of the district through 1959 was about 202,000 ounces. By far the most productive placers are outwash gravels which extend downstream from the moraines formed by the South Platte glacier; smaller deposits have been found upstream (Singewald, 1950, p. 146-161).
Almost all the gold production from the Tarryall district has come from placer deposits along the upper reaches of Tarryall Creek and its tributaries, northwest of the town of Como. Placer gold was discovered in August 1859, probably a little earlier than the discovery in the Fairplay district. These placers are credited with an output from 1859 to 1872 of about $1 million (48,380 ounces) (Henderson, 1926, p. 36, 187). Unrecorded and probably small-scale activity continued into the early 1900's. A brief resurgence occurred in 1941-42 and again in 1947, but the district was dormant from that time through 1959. The total minimum gold production from the Tarryall placers through 1959 was about 67,000 ounces. Lode mines in the district yielded less than 250 ounces of gold. The placer deposits are of two kinds: glacial moraines and outwash gravel deposits downstream from the moraines (Singewald, 1950, p. 147-148, 162-168). The bulk of the gold has been mined from outwash deposits where the gold is concentrated just above bedrock; however, all the gravel contains some gold.
