@misc{indiciae6d02707246eb,
  title = {Geologic map of the Old Faithful quadrangle, Yellowstone National Park, Wyoming},
  author = {Robert L. Christiansen and H. Richard Blank},
  year = {1974},
  doi = {10.3133/gq1189},
  url = {https://pubs.usgs.gov/publication/gq1189},
  note = {Source identifier: gq1189}
}