In the U.S.A, the western diamondback rattlesnake is found in central and western Arkansas, Oklahoma, Texas, southern and central New Mexico, southern and central Arizona, southern Nevada, and southeastern California. In Mexico it is found in Nuevo Leòn, Coahuila, Chihuahua, Sonora, northeastern Baja California, northern Sinaloa, northeastern Durango, Zacatecas, San Luis Potosì, northern Veracruz, Hidalgo,and Querètaro. Some have been found on islands in the Gulf of California, like San Pedro Màtir, Santa Marìa, and Tìburon.