@misc{indiciae6ac305ae0c98,
  title = {The regional aquifer system underlying the Northern Great Plains in parts of Montana, North Dakota, South Dakota, and Wyoming; summary},
  author = {J. S. Downey and G.A. Dinwiddie},
  year = {1988},
  doi = {10.3133/pp1402a},
  url = {https://pubs.usgs.gov/publication/pp1402A},
  note = {Source identifier: pp1402A}
}