@misc{indiciae3f07473cf5f0,
  title = {Generalized slope map of the Big Fork-Avon environmental study area, Flathead, Lake, Missoula, and Powell counties, Montana},
  author = {I. J. Witkind and J.M. Boyles and Penny E. Patterson},
  year = {1979},
  doi = {10.3133/i1130},
  url = {https://pubs.usgs.gov/publication/i1130},
  note = {Source identifier: i1130}
}