Copper Mining in Michigan - White Pine Mine

White Pine Mine

The copper-bearing Nonesuch Shale at the south end of the Copper Country in Ontonagon County had been known since the 1800s. But the ore grades were too low, the ore mineral particles too small, and the copper was largely in sulfides instead of native copper. All these conditions made the shale deposits uneconomical, although repeated attempts were made to mine the shale at the Nonesuch mine.

In 1955 the Copper Range Company began large-scale mining at the White Pine mine, near the old Nonesuch mine. The deposit is a stratiform deposit in the lower 15 m of the Proterozoic Nonesuch Shale and the upper 2 m of the underlying Copper Harbor Conglomerate. The principal ore mineral was chalcocite, although native copper predominated in the lower part of the beds. The mine was very successful, producing more than 1.8 million metric tons of copper during its life. The White Pine mine, the last major copper mine in Michigan, shut down in 1995.

The company applied to government agencies to continue mining by in-situ leaching, using sulfuric acid to recover an additional 900 million pounds of copper by SX-EW. The Michigan Department of Environmental Quality approved the permit in May 1996, and White Pine installed a pilot in-situ leaching project. Native Americans of the Bad River Indian Reservation in northern Wisconsin blockaded rail shipments of sulfuric acid to the mine (see Bad River Train Blockade); the mine began receiving acid shipments by truck. The U.S. Environmental Protection Agency (EPA), which had previously held that it had no role in the permitting, reversed itself, and stated that White Pine would have to apply for a federal permit. White Pine, which had already started to recover copper from the pilot project, suspended solution mining in October 1996, and applied for to the EPA for the permit. In May 1997 the company withdrew the EPA permit application, saying that further permitting delays had made the project uneconomical, and announced plans to begin reclamation of the mine site.

The tailings impoundment at the White Pine Mine is presently the site of significant environmental degradation. The University of Montana undertook extensive efforts to restore and revegetate the barren landscape from 1997-1999, but it is unclear whether this has been successful. The university has published a detailed report of its project. Satellite images are available at (46°47′17.91″N 89°31′47.97″W / 46.7883083°N 89.5299917°W / 46.7883083; -89.5299917).

In 2012, SubTerra used the mine for pharmaceutical research.