Mine: Trimountain Mine, Trimountain, MI


Began → Trimountain Mine → Closed

From: 1899

Owned by: Trimountain Mining Company, then Copper Range Consolidated Co. in 1925.

Produced: Copper ore

Method: Underground mine.

Railroad connection: COPR

Stamp Mill/Smelter: On Lake Superior near Freda.

Until: 1930

Lifetime Production:  144 million lbs of refined copper.


Trimountain Mine was located in its namesake town about 10 miles southwest of Houghton. Operations began about 1899 by the Trimountain Mining Company and the mine ultimately had four shafts.


An underground copper mine consisting of 4 shafts near the community of Trimountain. The Trimountain Mining Co. was organized in 1899 and worked the Baltic Lode. Shafts at this mine were some of the steepest in the Keweenaw at 70 degrees from horizontal to follow the orebodies. The mine opereated under Trimountain until 1923, when the company was dissolved. Copper Range Consolidated Co. took over operations in 1925 and operated the mine until 1930 when it was closed permanantly. The Trimountain Mine produced approx. 144 million lbs. of refined copper. Some minerals that can be found on the piles include copper, epidote, datolite, and rarely chalcocite. [MINDAT]


July 13, 1901. Trimountain shaft No. 1 is down 700 feet and there is drifting underway at all levels to and including the fourth level. Butlittle work is being done at No. 2 shaft. The comp;leted branch of the Copper Range railroad is delivering building material at the Trimountain mill site.