@misc{indiciae135fe28d9ec4,
  title = {Historic trail map of the Denver 1 degree by 2 degrees Quadrangle, central Colorado},
  author = {G. R. Scott},
  year = {1999},
  doi = {10.3133/i2639},
  url = {https://pubs.usgs.gov/publication/i2639},
  note = {Source identifier: i2639}
}