@misc{indiciaebf34e372ec0b,
  title = {Geologic and tectonic maps of the Bearpaw Mountains area, north-central Montana},
  author = {B. C. Hearn},
  year = {1976},
  doi = {10.3133/i919},
  url = {https://pubs.usgs.gov/publication/i919},
  note = {Source identifier: i919}
}