@misc{indiciaefef87e531149,
  title = {Claim map, Gypsum Gap quadrangle, San Miguel County, Colorado},
  author = {Raymond Dewey Sample and Howard F. Albee},
  year = {1961},
  doi = {10.3133/ofr61140},
  url = {https://pubs.usgs.gov/publication/ofr61140},
  note = {Source identifier: ofr61140}
}