OTHER RESOURCES OF MICHIGAN 89 



tribution, such as northeastern Ontonagon County 

 (Minnesota and Michigan mines), near Portage 

 Lake (Isle Royale and Quincy mines), near the 

 boundary of Houghton and Keweenaw counties 

 (Calumet and Hecla, Ahmeek, Wolverine and 

 Mohawk mines), and near Eagle River (Cliff, Phoenix 

 and Keweenaw Copper Company's mines). Con- 

 trary to an impression sometimes encountered, there 

 is no mining of copper beneath Lake Superior, but 

 the copper deposits emerge on Isle Koyale and other 

 islands in Lake Superior and on its Canadian shore, 

 but in amounts that have seldom been remunerative 

 to its miners. Some of the mines on the Copper 

 Range have been operated for many years, a very 

 few having their inception before 1850. The de- 

 posits are manifestly very far from being exhausted. 

 The metal is being secured in some instances from 

 shafts extending to a depth of more than a mile, 

 which makes costs high; nor is the ratio of copper 

 recovered to the rock raised to the surface high, in 

 some instances amounting to ten or eleven pounds 

 of metal to the ton of rock in mines that have, 

 nevertheless, been operated at a profit. 



Unlike iron ore, copper when elevated to the sur- 

 face must be "stamped" to dislocate the metal from 

 its rock container, and this process is performed 

 where there is ample supply of water, at present on 

 Portage and Torch lakes and, in most instances, on 

 the shore of Lake Superior. Unlike iron ore, too, 

 much of the metal is smelted in the same district 

 where it is mined. A leeching plant at Lake Linden 



