@misc{indiciaecc77e889fd82,
  title = {Digital mining claim density map for federal lands in California: 1996},
  author = {Paul C. Hyndman and Harry W. Campbell},
  year = {1999},
  doi = {10.3133/ofr99409},
  url = {https://pubs.usgs.gov/publication/ofr99409},
  note = {Source identifier: ofr99409}
}