@misc{indiciae66c1551bba8d,
  title = {Hydrologic Unit Map-1978, state of South Dakota},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1978},
  doi = {10.3133/hu41},
  url = {https://pubs.usgs.gov/publication/hu41},
  note = {Source identifier: hu41}
}