The following information is courtesy of the Arizona Partners in Amphibian and Reptile Conservation. Each link will open in a new browser window. And, each page gives you complete details about that particular species, including the georgraphic areas of Arizona where they normally reside. Thank you to the AZPARC.
Venomous Snakes
Arizona Black Rattlesnake aka: Crotalus cerberus
Arizona Ridgenosed Rattlesnake aka: Crotalus willardi
Black-tailed Rattlesnake aka: Crotalus molossus
Desert Massasauga Rattlesnake aka: Sistrurus catenatus
Hopi Rattlesnake aka: Crotalus viridis nuntius
Mojave Rattlesnake aka: Crotalus scutulatus
Prairie Rattlesnake aka: Crotalus viridis
Rock Rattlesnake aka: Crotalus lepidus
Sidewinder aka: Crotalus cerastes
Sonoran Coral Snake aka: Micruroides euryxanthus
Speckled Rattlesnake aka: Crotalus mitchelli
Tiger Rattlesnake aka: Crotalus tigris
Twin Spotted Rattlesnake aka: Crotalus pricei
Western Diamond-backed Rattlesnake aka: Crotalus atrox
Western Rattlesnake aka: Crotalus oreganus
Mildly Venomous Snakes
Brown Vine-Snake aka: Oxybelis aeneus
Chihuahuan Black-Headed Snake aka: Tantilla wilcoxi
Night Snake aka: Hypsiglena torquata
Plains Black-Headed Snake aka: Tantilla nigriceps
Ring-Necked Snake aka: Diadophis punctatus
Smith's Black-Headed Snake aka: Tantilla hobartsmithi
Western Hog-Nosed Snake aka: Heterodon nasicus
Western Lyre-Snake aka: Trimorphodon biscutatus
Yaqui Black-Headed Snake aka: Tantilla yaquia
Mildly Toxic Snakes
Ground-Snake aka: Sonora semiannulata
Sonoran Shovel Nosed Snake aka: Chionactis palarostris
Variable Sand-snake aka: Chilomeniscus stramineus
Western Shovel Nosed Snake aka: Chionactis occipitalis
Personal Experience: Last year, I went to take a book back to the library, through the night book drop. It was dusk, and as I was returning to my vehicle, I encountered a fairly large diamond-back snake. Dumb me left the cell phone in the car, so I had to walk around the snake and pray that no snake babies were between me and my car. Diamond-Backs will strike to protect their young!