@misc{indiciae645d0088b25c,
  title = {Coal resource occurrence and coal development potential maps of the Otter Quadrangle, Powder River County, Montana},
  author = {E. J. McKay and Laura N. Robinson},
  year = {1979},
  doi = {10.3133/ofr79105},
  url = {https://pubs.usgs.gov/publication/ofr79105},
  note = {Source identifier: ofr79105}
}