Blue = range of H. o. klauberi
Click the map for a key to subspecies
Grismer, L. Lee. Amphibians and Reptiles of Baja California, Including Its Pacific Islands and the Islands in the Sea of Cortés
. The University of California Press, 2002.
McPeak, Ron H. Amphibians and Reptiles of Baja California.
Sea Challengers, 2000.
Samuel M. McGinnis and Robert C. Stebbins. Peterson Field Guide to Western Reptiles & Amphibians
. 4th Edition. Houghton Mifflin Harcourt Publishing Company, 2018.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians
. 3rd Edition. Houghton Mifflin Company, 2003.
San Diego Natural History Museum