Montana Copper mining in the United States

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the berkeley pit, butte, in may 1984.


in 2006, montana fourth-largest copper-producing state in country.


butte, montana once nation’s prolific copper-mining district. miners first came butte in 1864 mine placer gold. hard rock silver mining began in 1874, rich copper veins discovered in 1882. district switched silver copper, , 1887, butte leading copper-producing district in united states. anaconda copper mine world s productive copper mine 1892 through 1903, , intermittently years thereafter. open-pit mining began @ berkeley pit in 1955; berkeley pit has been inactive years, , continues fill acidic water. through 1964, butte produced 7.3 million tonnes of copper, 2.2 million tonnes of zinc, 1.7 million tonnes of manganese, 380 thousand tonnes of lead, 645 million troy ounces of silver, , 2.5 million ounces of gold. remaining active copper mine @ butte continental pit, operated montana resources llp.


some copper produced troy unit silver mine in northwest corner of state, , 2 platinum mines in stillwater igneous complex: stillwater mine , east boulder project.








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