Silver Prospecting and Mining

SILVER PROSPECTING AND MINING

SILVER PROSPECTING AND MINING. Silver mining in North America began when the Spanish worked small mines during their occupation of New Mexico, California, and Texas. New Hampshire produced small amounts of silver after 1828, as well as Virginia and Tennessee after 1832. Large-scale silver mining had its beginning in Nevada after 1859, when Peter O'Riley and Patrick McLaughlin prospected the area eastward from the California gold fields and staked what would become known as the Comstock lode. Though looking for gold, their discovery developed into a bonanza mine that yielded ores so rich that within two decades more than $300 million worth of silver and gold had been extracted.

The Comstock pattern, in which prospectors discovered silver while searching for gold, was repeated in various parts of the American West. At Georgetown, Colorado, an original gold placer camp developed as the center of a silver-producing district after the opening of the Belmont lode in 1864. Also in Colorado, the gold camp of Oro City was almost a ghost town when prospectors discovered carbonate of lead ores with rich silver content in 1877, rapidly transforming the town into the greatest of Colorado silver cities, Leadville. Gold prospectors also accidentally discovered the Bunker Hill and Sullivan mines in the Coeur d'Alene district of Idaho.

Silver occurs in lodes or veins that run to great depths underground. Prospectors identify the lode by the outcroppings of such ores. The silver can be recovered by crushing the ore in a stamp mill. This process passes the ore over copper plates coated with mercury and then separates the amalgam by driving off the mercury with heat. Other, more complex, forms of silver are chemically combined with gold, lead, copper, or other metals. The identification of these ores is much more difficult and requires more intricate metallurgical processes for separation. Mills and smelters necessary for treating complex silver ores were not available in the United States until 1866–1868. Thomas H. Selby in San Francisco, W. S. Keyes in Eureka, Nevada, A. W. Nason in Oreana, Nevada, and Nathaniel P. Hill in Blackhawk, Colorado, were all pioneers of the smelting industry in the United States. As a result of their advances in smelting technology, recovered metals such as lead and copper became increasingly significant by-products of the silver smelters.

The prosperity of the silver mining industry in the United States during the nineteenth century was intimately related to the currency policy of the federal government, particularly after the demonetization of silver in 1873. Many of the largest producing silver mines in the country opened after 1873. During the quarter of a century that followed, the nation debated the questions of silver purchases and coinage. The huge quantities of silver produced by these mines depressed the price, and, with the repeal of the Sherman Silver Purchase Act in 1893, the domestic silver market fell to levels so low that many mines suspended operations.

The industry recovered sufficiently to make the years 1911–1918 the peak years in volume of production. An annual average of 69,735,000 fine ounces of silver were produced during those years. After those boom years the continuing low prices for silver and high production costs limited activity in mining. After 1920 the Coeur d'Alene district of Idaho was the leading silver-producing region in the country. In 1970 Idaho produced 42 percent of the 45,006,000 fine ounces of silver mined in the United States, while most of the other silver came from mines in Arizona, Utah, and Montana.

BIBLIOGRAPHY

Bakewell, Peter, ed. Mines of Silver and Gold in the Americas. Brookfield, Vt.: Variorum, 1997.

Paul, Rodman W. Mining Frontiers of the Far West, 1848–1880. New York: Holt, Rinehart, and Winston, 1963.

Rickard, T. A. A History of American Mining. New York: McGraw-Hill, 1932.

Smith, Duane A. Mining America: The Industry and the Environment, 1800–1980. Lawrence: University Press of Kansas, 1987.

Carl Ubbelohde / h. s.

See also Leadville Mining District ; Mining Towns ; and vol. 9: Roughing It .