Mine: Mass Mine, MI (Ontonagon County)

An underground copper mine consisting of three shafts adjacent to Mass City, MI. The Mass Mining Co. was organized in 1856 and worked sporadically until 1888, when the mine operations ceased for good. The mine was merged into the Mass Consolidated Mining Co. in 1899. A wide range of minerals can be found at the original Mass Mine site, including copper, silver, and datolite. [MINDAT]

Note: The Old Mass Mine was organized in 1856 to work the property formerly known as the Johnson Pre-Emption or Johnson Tract. The mine worked one shaft that was sunk when it was the Johnson Tract. Between 1856 and 1860, six shallow shafts were sunk. Work was suspended in 1860 and resumed in 1864 when work focused on the Evergreen Lode. Work was again stopped in 1868 and the mine was worked on tribute until 1874. The company resumed mining in 1875 until it again closed the mine in 1884. The mine was worked on tribute until 1889 when the mine became part of the Mass Consolidated Mining Company. Between 1856 and 1888, the mine produced approximately 4.8 million pounds of copper. Today, the rock piles produce fine specimens of copper, silver, datolite, and several micro minerals. [MINDAT]