| Northern Pacific Rattlesnake
Crotalus oreganus Holbrook, 1840
- Ashton and de Queiroz (2001 Molecular Phylogenetics and Evolution 21(2): 176-189), using mtDNA, concluded that this wide-ranging taxon consisted of two strongly divergent clades, and recommended that they be recognized as two distinct species, Crotalus viridis (including the nominate subspecies and the race nuntius) and Crotalus oreganus (including the remaining races). Under this arrangement, the standard common name for Crotalus viridis became Prairie Rattlesnake and that for Crotalus oreganus became Western Rattlesnake.
- Collins & Taggart (2002 Standard Common and Current Scientific Names for North American Amphibians, Turtles, Reptiles, and Crocodilians. Fifth Edition) submitted for consideration the proposal by Ashton & de Queiroz (2001 op. cit.) to a snake systematist group composed of Frank T. Burbrink, Jeff Camper, Harry W. Greene, L. Lee Grismer, Robin Lawson, James R. McCranie, Andrew H. Price, Javier Rodriguez-Robles, and Samuel S. Sweet, and they agreed.
- Douglas, Douglas, Schuett, Porras, & Holycross [2002. Phylogeography of the Western Rattlesnake (Crotalus viridis) Complex, with emphasis on the Colorado Plateau]. Pp. 11-50. In Biology of the Vipers [Schuett, Höggren, Douglas, and Greene (editors). Eagle Mountain Publishing, Eagle Mountain, Utah. xii + 580 pp. + 16 color plates] recognized this taxon as a distinct species, C. oreganus. Standard common name becomes Northern Pacific Rattlesnake.
- Hoser (2009. A reclassification of the Rattlesnakes; species formerly exclusively referred to the genera Crotalus and Sistrurus. Australasian Journal of Herpetology 6: 1-21), retained this species in the genus Crotalus Linnaeus 1758.
- Collins & Taggart (2009 Standard Common and Current Scientific Names for North American Amphibians, Turtles, Reptiles, and Crocodilians. Sixth Edition) submitted for consideration the proposal by Douglas et al. (2002 op. cit.) to a snake systematist group composed of Frank T. Burbrink, Jeff Camper, Michael Douglas, Harry W. Greene, Toby Hibbitts, Robin Lawson, James R. McCranie, Brice P. Noonan, Christopher L. Parkinson, Theodora Pinou, R. Alexander Pyron, Javier A. Rodriguez-Robles, and Van Wallach, and a majority of those responding agreed.