@misc{indiciae76ec04503b52,
  title = {State hydrologic unit maps},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1987},
  doi = {10.3133/70039553},
  url = {https://pubs.usgs.gov/publication/70039553},
  note = {Source identifier: 70039553}
}