@misc{indiciae472779337d3d,
  title = {Geologic map of Glacier National Park, Montana},
  author = {James W. Whipple},
  year = {1992},
  doi = {10.3133/i1508f},
  url = {https://pubs.usgs.gov/publication/i1508F},
  note = {Source identifier: i1508F}
}