Many would say that they height of large-scale gold mining in the United States is largely over. Regulations make it much more difficult to mine in the U.S. compared to many other countries, but there are still a handful of large open-pit mining operations here.
Below are 5 of the largest mines currently in operation that are producing gold and a variety of other minerals.1) Goldstrike Mine
Opened in 1986, the Goldstrike Mine is run by the world's largest gold mining company in Barrick Gold, and it is located on the Carlin Trend. Goldstrike is considered to have the largest gold deposit in the world and is the largest gold mine in North America. This mine has produced 35,000,000 ounces of gold which adds up to 1,100 tons. The Goldstrike Complex has underground and open-pit mines. The Meikle and Rodeo underground mines are located north of the Betze-Post open-pit, and these mines are operated by trucks and electric shovels.
There are 2 processing methods that Goldstrike miners use. The property's non-carbonaceous sulfide ore is treated by an autoclave circuit, and carbonaceous ore are processed by a roaster. Ores that are processed come from both surface and underground operations. Goldstrike's probable mineral reserves amount to 9.6 million ounces of gold.2) Carlin Trend Gold Mine
Numerous open-pit gold mines make up the Carlin Trend as it is based in northeastern Nevada just outside of Elko. Gold mining began in Carlin, Nevada in 1965 by the Newmont Mining Corporation. Mining with open pits, and some have been extended to underground mining since 1994. Newmont operated on 13 open pits in 2005 along with 4 underground mines and 14 active processing facilities.
Newmont produces around 2.5 million ounces of gold per year from this mine. The major source of Carlin Trend ore are the open-pit mines and conventional mining methods such as large shovels and haulers are used.
A fun fact about Newmont would be that they were the pioneers of the method that involved open-pit mining with cyanide heap leach recovery of gold.
3) Fort Knox Gold Mine
Currently run by Kinross Gold and based in Fairbanks, Alaska, the Fort Knox Gold Mine was originally staked in 1913 and then restaked by Amax Gold in 1980. Amax Gold would agree to a merger with Kinross Gold in 1998. Just like Carlin Trend, mining in Fort Knox involves conventional open-pit methods and all mining is done in a year-round basis. A carbon-in-pulp mill is used to process high-grade ore, with a daily capacity of 33,000 to 45,000 tons being processed. Heap leach production of ore in Fort Knox was implemented in late 2009. Fort Knox covers 332 acres and has processed a total of 2.4 million ounces.Huge Gold Nugget DiscoveriesState-by-State Gold Map
4) Cripple Creek and Victor Gold Mine
Based in Colorado Springs, Colorado, the Cripple Creek and Victor Gold Mine features gold deposits that stretch as far as 7 square miles, which contain volcanic-intrusive complex. The Cripple Creek mining district originally formed in 1891 and the town of Victor was built in 1893. From 1894 to 1917 there were more than 500 mines operating in the district. The mining district was shut down in 1941 due to World War II, but it eventually reopened in 1976 with the help of a joint venture between Texasgulf and Golden Circle.
The amount of ore mined in 2014 was 21,000,000, and the gold produced at this site was estimated at 211,000 troy ounces. Production costs amounted to $475 per ounce. Miners at Cripple Creek historically reached depths of around 3,000 feet in shafts, but in recent times it has mainly been about surface mining. At Cripple Creek there is a mining facility for extracting higher grade ores.5) Cortez Gold Mine
Southwest of Elko, Nevada sits the Cortez Gold Mine as conventional open-pit methods are used to mine its Pipeline and South Pipeline deposits. The size of the Cortez property is quite large as it extends to 2,800 square kilometers, containing mineral trends that are some of the world's most highly prospective. There are 3 different metallurgical processes that are used to recover gold at Cortez. The heap leaching method is used to extract lower grade oxide ore. There is also the conventional mill with cyanidation and a carbon-in-leach process that is used to extract higher grade non-refractory ore. During the mining of deposits found in the Pipeline and South Pipeline, there is also the intermittent mining of carbonaceous mill ore.
Approximately 9.85 million ounces of proven and probable gold reserves have been processed by Cortez miners.