@misc{indiciae328e8983f71a,
  title = {Preliminary maps and reports released by the Geologic Division, 1946-47, and by the Conservation Division, 1938-47},
  author = {Ruth A. Atherton and W.H. Eckstein and R.E. Spratt},
  year = {1949},
  doi = {10.3133/cir56},
  url = {https://pubs.usgs.gov/publication/cir56},
  note = {Source identifier: cir56}
}