@misc{indiciae135295beec48,
  title = {Geologic map of the Rapid City NW Quadrangle, Meade and Pennington counties, South Dakota},
  author = {Edward E. McGregor and J. Mark Cattermole},
  year = {1972},
  doi = {10.3133/ofr72240},
  url = {https://pubs.usgs.gov/publication/ofr72240},
  note = {Source identifier: ofr72240}
}