Petersen, Max S.2007-01-032022-02-032007-01-032022-02-03http://hdl.handle.net/11124/5862Date scanned: 2002-5-21.USBM #59708; Drilling side "caving back" operation. Sub-level caving system of mining. Sixth level. Cambria Mine, Cleveland-Cliffs Iron Company, Negaunee, Marquette County, Michigan.Held in the Russell L. and Lyn Wood Mining History Archive, Arthur Lakes Library, Colorado School of Mines.Donor: United States Bureau of Mines.The first iron ore in the Lake Superior region was found on the site of the Jackson Mine, leading to discoveries of the extensive Lake Superior iron ore deposits in the Marquette Range. The Jackson pit mine was opened in 1848 by prospectors from Jackson, Michigan who formed the Jackson Mining Company. The Cambria Mine, which opened in 1874, was eventually included in the property. The Cambria-Jackson Mine was consolidated with the Mather Mine, which began shipping ore in 1943. These properties were operated by the Cleveland-Cliffs Iron Company. The Mather Mine was the last underground iron mine operating in Michigan and finally closed in 1979. Cleveland-Cliffs Iron Company was formed with the merger of two major iron mining companies on Michigan's Marquette Range in 1891. The Company had a number of mines operating in the Upper Peninsula by the outbreak of World War I. By the 1940s the high grade iron ores mined underground were becoming depleted. The Company developed a process to concentrate low grade ores into iron ore pellets in the 1950s, and C. C. I. C.'s last underground iron mine closed in 1979.Rights management statement available at: http://library.mines.edu/digital/rights.htmlCleveland-Cliffs Iron CompanyIron mines and miningMinersMiningScenes, undergroundUnderground miningStillImage