@misc{indiciaecddcd284e61a,
  title = {Preliminary geologic map of the Mount Vernon 7 1/2' Quadrangle, Skagit County, Washington},
  author = {David P. Dethier and John T. Whetten},
  year = {1981},
  doi = {10.3133/ofr81105},
  url = {https://pubs.usgs.gov/publication/ofr81105},
  note = {Source identifier: ofr81105}
}