@misc{indiciae42ef93411784,
  title = {Map showing mines, prospects, and areas of significant silver, lead, and zinc production in the Aspen quadrangle, Pitkin County, Colorado},
  author = {Bruce Bryant},
  year = {1972},
  doi = {10.3133/i785d},
  url = {https://pubs.usgs.gov/publication/i785D},
  note = {Source identifier: i785D}
}