@misc{indiciae58bf07d76ada,
  title = {Hydraulic map of Horn Creek Rapids, Grand Canyon, Arizona},
  author = {S. W. Kieffer},
  year = {1988},
  doi = {10.3133/i1897e},
  url = {https://pubs.usgs.gov/publication/i1897E},
  note = {Source identifier: i1897E}
}