@misc{indiciae192e3a319173,
  title = {Geologic map and coal sections of the Pine Butte School Quadrangle, Big Horn County, Montana},
  author = {W. J. Mapel},
  year = {1978},
  doi = {10.3133/mf1014},
  url = {https://pubs.usgs.gov/publication/mf1014},
  note = {Source identifier: mf1014}
}