@misc{indiciaed875ce72a227,
  title = {Geologic map of the Niwot quadrangle, Boulder County, Colorado},
  author = {Donald E. Trimble},
  year = {1974},
  doi = {10.3133/ofr7410},
  url = {https://pubs.usgs.gov/publication/ofr7410},
  note = {Source identifier: ofr7410}
}