Gold mining in the United States
[1] Some minor gold production took place in North Carolina as early as 1793, but created no excitement.
The discovery on the Reed farm in 1799 which was identified as gold in 1802 and subsequently mined marked the first commercial production.
Most gold produced today in the US comes from large open-pit heap leach mines in the state of Nevada.
Mountain man Pauline Weaver discovered placer gold on the east side of the Colorado River in 1862.
[13] The gold-bearing quartz veins of the Vulture Mine, southwest of Wickenburg, in Maricopa County were discovered in 1863.
Spanish prospectors found gold in the Potholes district between 1775 and 1780, along the Colorado River, in present Imperial County, California, about ten miles northeast from Yuma, Arizona.
Other placer deposits on the west bank of the Colorado River were quickly found, including the Picacho and Cargo Muchacho districts.
In 1849, people started hearing about the gold and after just a few years San Francisco's population increased to thousands.
Gold production in California peaked in 1852, at 3.9 million troy ounces (121 tonnes) produced in that year.
But the placer deposits worked in the early years were quickly exhausted, and production crashed.
[16] The largest gold-mining district in California is the famous Mother Lode of the Sierra Nevada.
The gold of the Mother Lode is in quartz veins within phyllite, schist, slate, and greenstone.
The first important gold discoveries in Colorado were in the Central City-Idaho Springs district in January 1859.
[26] The French Creek-Florence district in Idaho County began in the 1860s, and has produced about 1 million troy ounces (31 tonnes) from placers.
The Silver City district in Owyhee County began producing in 1863, and made over 1 million troy ounces (31 tonnes), mostly from lode deposits.
The Coeur d’Alene district in Shoshone County has made 44,000 troy ounces (1,400 kg) of gold as byproduct to silver mining.
Placer gold was discovered at Great Falls near Washington, DC in 1861 during the American Civil War by Union soldiers from California.
After the war a number of mines were opened on gold-bearing quartz veins in Montgomery County.
The underground mine, originally operated from 1880 to 1897, and reopened from 1983 to 1989,[30] extracted gold from quartz veins in peridotite.
[34] Nevada is the leading gold-producing state in the nation, in 2018 producing 5,581,160 troy ounces (173.6 tonnes), representing 78% of US gold and 5.0% of the world's production.
Much of the gold in Nevada comes from large open pit mining and with heap leaching recovery.
Active major mines include Cortez, Twin Creeks, Betz-Post, Meikle, Marigold, Round Mountain, Jerritt Canyon and Getchell.
[37] In 1877, two prospectors collected float in the area of the future Opportunity Mine near Hillsboro, New Mexico, which was assayed at $160 per ton in gold and silver.
Prospectors from Illinois discovered placer gold in the Klamath Mountains of southwest Oregon in 1850, starting a rush to the area.
Kinross Gold Corporation's reclamation of the Haile site was nominated for a US Bureau of Land Management "Hardrock Mineral Environmental Award."
Most gold produced in Utah today is a byproduct of the huge Bingham Canyon copper mine, southwest of Salt Lake City.
[52] Gold was discovered at the South Pass-Atlantic City-Sweetwater district in present Fremont County in 1842.
The placers were worked intermittently until 1867, when the first important gold vein was discovered, and prospectors and miners rushed to the area..
This placer gold is found north of, or near the terminus of, Pleistocene, or earlier, moraines left by Ice Age glaciers that pushed gold-rich dirt down from Canada, where hard rock gold deposits do exist, and which were scoured by glaciers.
Small commercial operations have existed at various times, to mine this gold, with various degrees of limited success.
