@misc{indiciaec6ee0619a1e3,
  title = {Geologic map of the Chisos Mountains, Big Bend National Park, Texas},
  author = {Robert G. Bohannon},
  year = {2011},
  doi = {10.3133/sim3140},
  url = {https://pubs.usgs.gov/publication/sim3140},
  note = {Source identifier: sim3140}
}