The Ontario silver mine is a mine that was active starting in 1872, and is located near Park City, Utah,

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

History

The

lode In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fissure (or crack) in a rock formation or a vein of ore that is deposited or embedded between layers of rock. The current meaning (ore vein) dates from the 1 ...

was discovered by accident on 19 January 1872 by Herman Budden, Rector Steen (Pike), John Kain, and Gus McDowell. The mine was purchased by George Hearst through R. C. Chambers from the prospectors for $27,000 on 24 August 1872. Hearst and his business partners

James Ben Ali Haggin James Ben Ali Haggin (December 9, 1822 – September 12, 1914) was an American attorney, rancher, investor, art collector, and a major owner and breeder in the sport of Thoroughbred horse racing. Haggin made a fortune in the aftermath of the C ...

and Lloyd Tevis owned this mine and constructed the necessary infrastructure to make it productive, including hoists and stamp mill. The mine was not profitable for its first three years. According to legend, expenses of development substantially drained Hearst's financial resources. As a result of his straitened circumstances, Hearst sold his home and horses, and even dismissed his servants and enrolled his son

William Randolph Hearst William Randolph Hearst Sr. (; April 29, 1863 – August 14, 1951) was an American businessman, newspaper publisher, and politician known for developing the nation's largest newspaper chain and media company, Hearst Communications. His flamboya ...

in public school. Chambers, who had been retained as manager, brought the bonanza ore body into production by the late 1870s. It eventually produced fifty million dollars' worth of silver and lead. By the time of Hearst's death in 1891, the Ontario mine had paid him more than $12 million in dividends. This was only one of the four big mines he had bought shares in and that were located in the West, including the Ophir on the

Comstock Lode The Comstock Lode is a lode of silver ore located under the eastern slope of Mount Davidson, a peak in the Virginia Range in Virginia City, Nevada (then western Utah Territory), which was the first major discovery of silver ore in the Unit ...

, the

Homestake Mine (South Dakota) The Homestake Mine was a deep underground gold mine (8,000 feet or 2,438 m) located in Lead, South Dakota. Until it closed in 2002 it was the largest and deepest gold mine in North America. The mine produced more than of gold during its lifetime ...

, and the

Anaconda Copper Mine (Montana) The Anaconda Copper Mine was a large copper mine in Butte, Montana that closed operations in 1947 and was eventually consumed by the Berkeley Pit, a vast open-pit mine. Originally a silver mine, it was bought for $30,000 in 1881 by an Irish i ...

. The mine also made manager Chambers one of Utah's Bonanza Kings. The Ontario mine was credited as being more consistent in yielding annual dividends during the late nineteenth century than any other mine in Utah. The Ontario company's mill was also the birthplace of two significant hydrometallurgical processes, the Russell Process and the Cyanide Process. Edward H Russell (Yale 1878) developed his process for working low grade silver ores by a leaching process, 1883–1884, and young Louis Janin (UC Berkeley) experimented with cyanide on the ores, filing a caveat to patent a cyanide process in 1886. Between 1874 and 1964, the Ontario Mine produced 41,289 ounces of gold, 55,710,608 ounces of silver, 164,231,209 pounds of lead, 210,350,684 pounds of zinc, and 3,911,102 pounds of copper. Primary ores included

argentiferous Silver mining is the extraction of silver from minerals, starting with mining. Because silver is often found in intimate combination with other metals, its extraction requires elaborate technologies. In 2008, ca.25,900 metric tons were consumed ...

galena Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It cr ...

sphalerite Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-V ...

, and

tetrahedrite Tetrahedrite is a copper antimony sulfosalt mineral with formula: . It is the antimony endmember of the continuous solid solution series with arsenic-bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the t ...

- tennantite with

pyrite The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic Luster (mineralogy), lust ...

and

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical f ...

gangue In mining, gangue () is the commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit. It is thus distinct from overburden, which is the waste rock or materials overlying an ore or mineral body ...

. The Ontario mine reopened as a tourist attraction in 1995, only to close again after a few years.A Look Back: Ontario Silver Mine in Park City
The Salt Lake Tribune, July 17, 2015.

References

Buildings and structures in Summit County, Utah Mines in Utah Hearst family 1872 in Utah Territory Landmarks in Utah Silver mines in the United States Stamp mills {{Utah-geo-stub