@misc{indiciae460c342646b2,
  title = {Mineral and energy resource assessment of the Helena National Forest, west-central Montana},
  author = {Russell G. Tysdal and S. D. Ludington and Anne E. McCafferty},
  year = {1996},
  doi = {10.3133/ofr96683a},
  url = {https://pubs.usgs.gov/publication/ofr96683A},
  note = {Source identifier: ofr96683A}
}