"Rattlesnake Formation". National Park Service. U. S. Department of the Interior. Retrieved 28 March 2021.
"Rattlesnake". National Park Service. U. S. Department of the Interior. Retrieved 28 March 2021.
oregongeology.org
Geologic Formations of Eastern Oregon (East of longitude 121°30'), 1972. John D. Beaulieu. Bulletin 73. Oregon Department of Geology and Mineral Industries.