@misc{indiciae4bc0201586ab,
  title = {Preliminary geologic map of the Fort Logan Quadrangle, Jefferson, Denver, and Arapahoe counties, Colorado},
  author = {R. M. Lindvall},
  year = {1976},
  doi = {10.3133/mf831},
  url = {https://pubs.usgs.gov/publication/mf831},
  note = {Source identifier: mf831}
}