The Anaconda Copper Mining Company and the development of geological mine maps at Butte, Montana, 1890-1910

Geologists at the U.S. Geological Survey in the late 19th century laid the foundations for modern geological mine mapping, but the Anaconda Copper Mining Company, of Butte, Montana, was the first private-sector organization to systematically use geological mine maps on a significant scale. The mapping methodology developed by the Anaconda Company, and particularly by its chief geologist Reno Sales, in the first decade of the 20th century is still the basis for ore deposit mapping throughout the world.

The Anaconda Company focused on geological mine mapping as a direct result of disputes associated with the rich copper deposits at Butte. Court cases based on the Apex Law led to the shutdown of almost all mining in Butte in 1903, and underground warfare between rival groups of miners threatened many lives. Scientific mapping of the disputed orebodies proved the best way to resolve the disputes. The development of economic geology as a science is thus intimately linked to legal and economic pressures, and to the powerful personalities that dominated Butte, its politics, economy, and society, in the period between 1890 to 1910.

Using data from the Anaconda Collection at the University of Wyoming, field records from the U.S. Geological Survey, and published reports, this talk examines the origins of geological mine maps and places their development in a social and scientific context.