@misc{indiciaef94ceaeeaa76,
  title = {Geologic map of the Iris Quadrangle, Gunnison and Saguache counties, Colorado},
  author = {Jerry C. Olson},
  year = {1975},
  doi = {10.3133/ofr7563},
  url = {https://pubs.usgs.gov/publication/ofr7563},
  note = {Source identifier: ofr7563}
}