@misc{indiciaee324f3a39c2c,
  title = {Geochemical maps of the Madison Roadless Area, Madison and Gallatin counties, Montana},
  author = {F. S. Simons and R. E. Van Loenen},
  year = {1988},
  doi = {10.3133/mf1605c},
  url = {https://pubs.usgs.gov/publication/mf1605C},
  note = {Source identifier: mf1605C}
}