McKeel, B. K.; Love, J. D. & Crew, M. E. North-South Cross Section (North Half), Northern Powder River Basin, Wyoming., map, February 1973; (https://digital.library.unt.edu/ark:/67531/metadc957880/m1/1/: accessed April 25, 2024), University of North Texas Libraries, UNT Digital Library, digital.library.unt.edu; .