@misc{indiciae433073037390,
  title = {Map showing locations of exposures of limonitic rocks and hydrothermally altered rocks in the Butte 1° x 2° quadrangle, Montana},
  author = {L. C. Rowan and D. B. Segal},
  year = {1989},
  doi = {10.3133/i2050a},
  url = {https://pubs.usgs.gov/publication/i2050A},
  note = {Source identifier: i2050A}
}