- Butte Mining District (Summit Valley Mining District)
| Gammons, C. H., Szarkowski, J., & Stevenson, R. (2016) New investigations of the mineralogy of silver in the world-class porphyry-lode deposits of Butte, MT. Mining engineering Magazine website (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
Lexington Mine, Walkerville, Butte Mining District, Silver Bow County, Montana, USA