@misc{indiciae3b2aabe0c3b1,
  title = {Preliminary report on aggregate use and permitting along the Colorado Front Range},
  author = {David R. Wilburn and William H. Langer},
  year = {2000},
  doi = {10.3133/ofr00258},
  url = {https://pubs.usgs.gov/publication/ofr00258},
  note = {Source identifier: ofr00258}
}