Geology of the Butte Mining District

Click for route map


Start point

Alice pit on Daly Street

End point

Montana Tech Mineral Museum


Various streets in Butte


The pits are inaccessible, but geologic features can be viewed from a distance.

Total distance

Not given



The Butte mining district is one of the major mining districts of the world with continuous production from both underground and open pit mines for 119 years, from 1864 to 1983. During this time, mining activites at Butte have introduced many firsts in mining methods, techniques of mine mapping, and the detailed recording of geologic data. This field guide describes the geology of the mineral deposits, provides a geologic map of the district, and concludes with a tour of eight locations of interest, including Alice pit, Syndicate pit, Berkeley pit, the Emma and Orphan Boy veins of the Anaconda system, the World Museum of Mining, and the Montana Tech Mineral Museum.

Key Lithologic Features

  • Butte Quartz Monzonite, in places with pervasive sericitic alteration
  • 17-20 foot-wide siliceous vein with Cu-Fe-Zn ore minerals (in two outcrops)
  • excellent museum collection of Butte minerals


  • Rarus Fault exposed in Berkeley pit


Other Features

  • exhibit of historical mining equipment, methods, and life around the turn of the century in Butte


Zeihen, L.G., Berg, R.B., and McClernan, H.G., 1987, Geology of the Butte mining district, in Beus, S.S., ed., Centennial Field Guide Volume 2: Rocky Mountain Section of the Geological Society of America , p. 57-61.


Out of print. Check Digital access to this publication is available via the links in the references section above.