@misc{indiciae39c22b693084,
  title = {Geologic map of the Marble quadrangle, Gunnison and Pitkin Counties, Colorado},
  author = {David L. Gaskill and Larry H. Godwin},
  year = {1966},
  doi = {10.3133/gq512},
  url = {https://pubs.usgs.gov/publication/gq512},
  note = {Source identifier: gq512}
}