@misc{indiciae94e279871b34,
  title = {Map showing depth to bedrock, Colrain quadrangle, Massachusetts–Vermont},
  author = {C.J. Londquist},
  year = {1974},
  doi = {10.3133/mf572a},
  url = {https://pubs.usgs.gov/publication/mf572A},
  note = {Source identifier: mf572A}
}