@misc{indiciaeec1d4c19d47e,
  title = {Geologic map of the Bristol Head quadrangle, Mineral and Hinsdale Counties, Colorado},
  author = {Thomas August Steven},
  year = {1967},
  doi = {10.3133/gq631},
  url = {https://pubs.usgs.gov/publication/gq631},
  note = {Source identifier: gq631}
}