National Park Service, U S Department of the Interior, U. S. Department of the Interior, U.S. Department of the Interior, U. S. Department Of The Interior
U S Geological Survey, U S Department of the Interior, U. S. Department of the Interior, U.S. Geological Survey, U.S. Department of the Interior, U. S. Geological Survey, U. S. Department Of The Interior
A J Peterka, U S Department of the Interior, Bureau of Reclamation, A. J. Peterka, U. S. Department of the Interior, U.S. Department of the Interior, U. S. Department Of The Interior, Bureau Of Reclamation
U S Geological Survey, U S Department of the Interior, U. S. Department of the Interior, U.S. Geological Survey, U.S. Department of the Interior, U. S. Geological Survey, U. S. Department Of The Interior
Harlan D Unrau, U S Department of the Interior, National Park Service, Harlan D. Unrau, U. S. Department of the Interior, U. S. Department Of The Interior
Bureau of Reclamation, U S Department of the Interior, U. S. Department of the Interior, U.S. Department of the Interior, Bureau Of Reclamation, U. S. Department Of The Interior