I have 68 snakes listed here that are found in Arizona.  Would you believe 17 of them are poisonous??

Arizona elegans philipi                              Painted Desert Glossy Snake
Arizona occidentalis eburnata                  Desert Glossy Snake
Arizona occidentalis noctivaga                Arizona Glossy Snake
Chilomeniscus cinctus                                 Banded Sand Snake
Chionactis occipitalis annulata                Colorado Desert Shovel-nosed Snake
Chionactis occipitalis klauberi                 Tucson Shovel-nose Snake
Chionactis occipitalis occipitalis              Mojave Shovel-nose Snake
Chionactis palarostris organica                Organ Pipe Shovel-nose Snake
Coluber mormon                                            Yellow-bellied Racer
Crotalus atrox                                                Western Diamondback Rattlesnake
Crotalus cerastes                                           Sidewinder
Crotalus lepidus klauberi                           Banded Rock Rattlesnake
Crotalus mitchelli pyrrhus                          Southwestern Speckled Rattlesnake
Crotalus molosus molosus                           Black-tailed Rattlesnake
Crotalus pricei pricei                                   Twin-spotted Rattlesnake
Crotalus scutalatus scutulatus                   Mojave Rattlesnake
Crotalus tigris                                                Tiger Rattlesnake
Crotalus viridis abyssus                               Grand Canyon Rattlesnake
Crotalus viridis lutosus                                Great Basin Rattlesnake
Crotalus viridis nuntius                                Hopi Rattlesnake
Crotalus viridis viridis                                  Prairie Rattlsnake
Crotalus willardi                                            Ridge-nose Rattlesnake
Diadophis punctatus regalis                        Regal Ring-neck Snake
Gyalopion canum                                            Western Hooknose Snake
Gyalopion quadrangulare                            Desert Hooknose Snake
Heterodon nasicus kennerlyi                        Mexican Hognose Snake
Hypsiglena torquata deserticola                  Desert Night Snake
Hypsiglena torquata ochrorhyncha             Spotted Night Snake
Lampropeltis getula californiae                    California King Snake
Lampropeltis getula splendida                      Desert King Snake
Lampropeltis pyromelena pyromelena         Arizona Mountain King Snake
Lampropeltis triangulum taylori                    Utah Milk  Snake
Leptotyphlops humilis                                       Blind Snake
Lichanura trivirgata                                          Rosy Boa
Masticophis bilineatus bilineatus                   Sonoran Whipsnake
Masticophis flagellum                                       Coachwhip
Masticophis taeniatus taeniatus                     Desert Striped Whipsnake
Micruroides euryxanthus euryxanthus          Arizona Coral Snake
Oxybelis aeneus                                                 Mexican Vine Snake
Phyllorhynchus browni                                     Saddled Leaf-nosed Snake
Phyllorhynchus decurtatus                               Spotted Leaf-nosed Snake
Pituophis catenifer affinis                                  Sonoran Gopher Snake
Pituophis catenifer deserticola                         Great Basin Gopher Snake
Rhinocheilus lecontei lecontei                          Western Long-nose Snake
Salvadora deserticola                                         Big Bend Patch-nose Snake
Salvadora grahamiae grahmiae                        Mountain Patch-nose Snake
Salvadora hexalepis hexalepis                           Desert Patch-nose Snake
Salvadora hexalepis mojavensis                         Mojave Patch-nose Snake
Senticolis triaspis intermedia                              Green Rat Snake
Sistrurus catenatus edwardsi                              Desert Massasauga
Sonora semiannulata                                             Ground Snake
Tatilla atriceps                                                       Mexican Black-headed Snake
Tatilla wilcoxi                                                         Chihuahuan Black-headed Snake
Tatilla yaquia                                                          Yaqui Black-headed Snake
Thamnophix eques megalops                                 Northern Mexican Garter Snake
Thamnophis elegans vagrans                                 Wandering Garter Snake
Thamnophis rufipunctatus                                      Narrowhead Garter Snake
Trimorphodon biscutatus lambda                         Sonoran Lyre Snake