MillsCopper Country Heritage Guide - Types
While there existed a generous amount of mass copper in the district (copper that is removed from the ground in large chunks), the majority of copper deposits were found in an amygdaloid state. Here the copper exists as small flakes and pebbles formed like cement into the surrounding volcanic rocks. In order to remove the copper from this rock, it first had to undergo processing in a stamp mill. After that the retrieved copper would be sent to a smelter, where it would be melted down and formed into bars for shipment called ingots.
Stamping is a process of smashing the copper-bearing rock with essentially a large hammer. The brittle nature of the basalt surrounding the copper allowed for the hammer to break it off from the copper. After that a series of wash tables and jigs would work to separate the two types of rock, dumping the waste rock into nearby lakes or streams and sending the copper off to smelters for refining. Originally these stamps were driven by simple gravity, but as the Keweenaw mines got deeper and more advanced, the mills became more efficient and powerful as well. Soon these expansive buildings would grow to soaring heights, and the massive stamps inside would shake the ground with each and every blow.
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Tamarack City – Built in 1910, this towering complex is marked by rows of monolithic concrete towers, one of which still supports one of the mill’s massive iron stamps.
C&H Power House
Lake Linden – Producing some 8000 KW’s of power, this electric generating plant provided electricity to not only C&H’s massive mill complex, but also the mine itself some six miles away.
C&H Stamp Mills
Lake Linden – The C&H Stamp Mill complex was actually three mills in one: one mill for the Calumet Mine, one for the Hecla, and a reclamation plant to reprocess the tailings from both.
Calumet Mill Boiler House
Calumet – This large brick building is all that remains of C&H’s first stamp mill, built on the shore of Calumet Lake just north of the old mine site.
Central Stamp Mill
Central – While the mill itself has mostly rotted away, the vast mine tailings that it left behind can still be seen bordering the adjacent highway.
Freda – This sprawling foundation on the shore of Lake Superior punctuated with a soaring smoke stack are all that’s left of the region’s last operating stamp mill – closed in 1967.
Gay – Sprawled along Lake Superior for several miles this 300 acre desolate landscape is entirely man-made, a result of several decades of milling operations from the Mohawk and Wolverine mills.
Isle Royale Mill
Houghton – Buried within the hill overlooking a modern gas station are the remains of the old Isle Royale Stamp Mill, erected in 1901 to serve the mine of the same name.
Isle Royale Pump House
Houghton – The last remaining structure from the ruined Isle Royale Stamp Mill, this impressive sandstone building once housed the a massive steam pump used to deliver the millions of water needed by the mill each day.
Gay – The sprawling ruins of this massive stamp mill originally built in 1901 are marked by a towering 265 foot concrete smoke stack overlooking the neighboring community of Gay.
Mason – This massive dredging platform was part of a reclamation effort to recover previously discarded copper from the Quincy Mine’s massive mine tailings in Torch Lake.
Quincy Stamp Mills
Mason – Between 1890 and 1900 Quincy erected a sprawling milling facility here along Torch Lake, complete with a massive coal dock and short line railroad to connect it with its mine six miles away.
Quincy Turbine Building
Mason – This threes story concrete structure was built in 1921 to provide electric power to the neighboring mills.
Redridge – One of only three such structures ever built in the country, this massive steel dam was erected to provide water for the neighboring Atlantic and Baltic stamp mills.
Redridge Timber Crib Dam
Redridge – Built by the Atlantic Mine in 1894, this 50 foot high crib dam has now been transformed by time into a spectacular man-made waterfall.