Anaconda Copper ARCO merged with Anaconda Copper Mining Company of Montana in 1977. Anaconda's holdings included the Berkeley Pit and the Anaconda, Montana Smelter. ARCO founder Robert Orville Anderson stated "he hoped Anaconda's resources and expertise would help him launch a major shale-oil venture, but that the world oil glut and the declining price of petroleum made shale oil moot". The purchase turned out to be a regrettable decision for ARCO. A lack of experience with hard-rock mining and a sudden drop in the price of copper to below seventy cents a pound, the lowest in years, caused ARCO to suspend all operations in Butte, Montana. By 1983, only six years after acquiring rights to the "Richest Hill on Earth", the Berkeley Pit was completely idle. By 1986, some ARCO properties were sold to billionaire industrialist Dennis Washington, whose company, Montana Resources, operates a much smaller open-pit mine east of the defunct Berkeley Pit.
Anaconda Copper ARCO merged with Anaconda Copper Mining Company of Montana in 1977. Anaconda's holdings included the Berkeley Pit and the Anaconda, Montana Smelter. ARCO founder Robert Orville Anderson stated "he hoped Anaconda's resources and expertise would help him launch a major shale-oil venture, but that the world oil glut and the declining price of petroleum made shale oil moot". The purchase turned out to be a regrettable decision for ARCO. A lack of experience with hard-rock mining and a sudden drop in the price of copper to below seventy cents a pound, the lowest in years, caused ARCO to suspend all operations in Butte, Montana. By 1983, only six years after acquiring rights to the "Richest Hill on Earth", the Berkeley Pit was completely idle. By 1986 some ARCO properties were sol,d to billionaire industrialist Dennis Washington, whose company, Montana Resources, operates a much smaller open-pit mine east of the defunct Berkeley Pit.