@misc{indiciae4141fdd14f35,
  title = {Geologic map of Mount St. Helens, Washington prior to the 1980 eruption},
  author = {Clifford A. Hopson},
  year = {2008},
  doi = {10.3133/ofr2002468},
  url = {https://pubs.usgs.gov/publication/ofr2002468},
  note = {Source identifier: ofr2002468}
}