@misc{indiciae6a79f9e68ee1,
  title = {Map of alluvial valley floors and strippable coal in forty-two 7 1/2-minute quadrangles, Big Horn, Rosebud, and Powder River Counties, southeast Montana},
  author = {Harold E. Malde and J. Michael Boyles},
  year = {1976},
  doi = {10.3133/ofr76162},
  url = {https://pubs.usgs.gov/publication/ofr76162},
  note = {Source identifier: ofr76162}
}