@misc{indiciae7134c570888e,
  title = {Preliminary geologic map of the Comb Rock quadrangle, Lewis and Clark County, Montana},
  author = {R. G. Schmidt},
  year = {1966},
  doi = {10.3133/i468},
  url = {https://pubs.usgs.gov/publication/i468},
  note = {Source identifier: i468}
}