@misc{indiciaecc4d896ddf75,
  title = {Geologic Map of the San Luis Quadrangle, Costilla County, Colorado},
  author = {Michael N. Machette and Ren A. Thompson and Benjamin J. Drenth},
  year = {2008},
  doi = {10.3133/sim2963},
  url = {https://pubs.usgs.gov/publication/sim2963},
  note = {Source identifier: sim2963}
}