Rattlesnakes in Arizona

Large areas of desert habitat and dry weather conditions make Arizona a suitable environment for rattlesnakes. The state has 13 native rattlesnake species, all of which are potentially dangerous to humans. Some of them are found throughout Arizona, while others are found in just a small range within the state or are considered endangered.

  1. Large Rattlesnakes

    • Arizona is home to four large rattlesnake species. The largest is the western diamondback, which can grow to be 66 inches in length. It is found in all but the most southwestern counties of the state. The prairie rattlesnake grows to 64 inches in length and is found in the northeastern part of the state. The western rattlesnake is smaller, averaging 63 inches in length, but has a venom twice as powerful as the diamondback. It is found only in a small area in the northwestern part of the state. The speckled rattlesnake grows to around 51 inches in length on average, and lives in the western half of the state.

    Medium Rattlesnakes

    • Of the 13 species of rattlesnake in Arizona, three grow to around four feet in length. The Mojave rattlesnake grows to just over four feet and is considered the most venomous rattler in the U.S. It is found throughout the western and southern parts of the state. The black-tailed rattlesnake grows to be four feet in length on average. It lives in the southeastern part of the state and ranges northwest into central Arizona. The Arizona black rattlesnake grows to a little under four feet and lives throughout the center of the state from east to west.

    Small Rattlesnakes

    • The sidewinder, found in the southwestern portion of Arizona, is one of the smallest rattlesnakes found in the state. It grows to around 25 inches in length, on average, and is the only rattler species to have horn-like scales above its eyes. It also has a distinctive way of moving across hot sand in a sideways motion, limiting body contact. The tiger rattlesnake, which grows to around 35 inches in length, has a distinctive orange-brown coloration with dark stripes that give it a tiger pattern. It lives in a small area of south central Arizona.

    Endangered Rattlesnakes

    • Of the state's species, four are considered at risk and are legally protected. The massasauga rattlesnake, the state's smallest, grows to an average of 22 inches. It is considered rare and is found only in the extreme southeastern part of the state. The twin-spotted rattlesnake, also found only in the extreme southeast, grows to 26 inches in length and has a small rattle that is hard to hear. The ridge-nosed rattlesnake, which grows to 26 inches in length, is Arizona's official reptile. It lives in small populations in the southeast. The rock rattlesnake grows to almost three feet in length and is locally present only in the southeastern portion of the state.