At White Pine Mine, the underground mine was operated from the late 1800s through September 1995. Calumet and Hecla Mining Company was the first company to mine the White Pine Mine; however, a drop in copper prices closed the mine in 1920 and led to Copper Range Company's purchase of the property in 1929 at a sheriff's sale. Initial mining focused on native copper within the Nonesuch Formation. Between 1937 and 1950, activities at the mine focused primarily upon research and development of the ore body. In early 1952, when advances in mining processes verified that the copper mineral chalcocite could be successfully smelted, construction of the existing mine facility began and the first ore was mined a year later. Physical development and start of operations of the mill and smelting facilities occurred in 1954. The first copper from the new mine facility was produced in January 1955. In 1977, Copper Range Company was purchased by the Louisiana Land and Exploration Company. The refinery and continuous casting operations were added to the mine complex in 1981. Most of the operations were suspended in 1982 followed by a temporary shutdown in 1984 for approximately 12 months. Echo Bay Mines Limited purchased CRC in January 1985. In November of 1985, CRC employees, through an Employee Stock Ownership Plan ("ESOP"), bought and operated CRC until May 1989. At that time, the majority of CRC stock was purchased by a wholly owned subsidiary of Inmet Mining Corporation (formerly Metall Mining Corporation).