@misc{indiciaeb7d22aae9144,
  title = {Southwest quarter of the Boulder quadrangle, Montana},
  author = {D. M. Pinckney and G.E. Becraft},
  year = {1961},
  doi = {10.3133/mf187},
  url = {https://pubs.usgs.gov/publication/mf187},
  note = {Source identifier: mf187}
}