@misc{indiciae1e64ccac2201,
  title = {Active-, inactive-, and abandoned-mine information and selected geochemical data for the State of Colorado},
  author = {Jean L. Ryder},
  year = {1994},
  doi = {10.3133/ofr94579},
  url = {https://pubs.usgs.gov/publication/ofr94579},
  note = {Source identifier: ofr94579}
}