@misc{indiciae1b3dd39179a6,
  title = {Map showing natural land slopes, Port Townsend quadrangle, Puget Sound region, Washington},
  author = {J. E. Frederick},
  year = {1979},
  doi = {10.3133/i1198a},
  url = {https://pubs.usgs.gov/publication/i1198A},
  note = {Source identifier: i1198A}
}