@misc{indiciae709e9e9ff5db,
  title = {Fifteenth Annual report of the United States Geological Survey to the Secretary of the Interior, 1893-1894},
  author = {John Wesley Powell},
  year = {1895},
  doi = {10.3133/ar15},
  url = {https://pubs.usgs.gov/publication/ar15},
  note = {Source identifier: ar15}
}