Discover the Largest Rattlesnake in Arizona

Western Diamondback Rattlesnake (Crotalus atrox)
© Alexander Wong/

Written by Taiwo Victor

Updated: November 16, 2023

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Arizona is located in the southwestern part of the United States and is the 6th largest and 14th most populous of the 50 states. Although Arizona is primarily known as a desert state, it also has climates supporting different kinds of animals such as birds, large predators, and reptiles. Rattlesnakes are among the most well-known of the roughly 4,000 species of snakes in the world. These creatures belong to the genera Crotalus and Sistrurus of the subfamily Crotalinae (the pit vipers). It is worth noting that all rattlesnakes are vipers, and the easiest way to identify them is by the rattle at the end of their tail that makes a loud noise to deter passers-by. 

Arizona is home to the highest number of rattlesnakes in the United States, with over 15 different types. The state’s official reptile is the Arizona ridge-nosed rattlesnake found in the “sky island” where Arizona meets Mexico. In this article, we’ll discover the largest rattlesnake in Arizona.

Rattlesnakes in Arizona

The majority of rattlesnakes in the United States are in Arizona. These snakes seek to avoid people as much as possible, yet they are dispersed over a wide area. Arizona state law protects four species of rattlesnakes, while a license is required to hunt any other varieties. There are several types of rattlesnakes in Arizona, and here are a few: 

1. Arizona Ridge-Nosed Rattlesnake 

Arizona Ridge-nosed Rattlesnake, Crotalus willardi

Averaging just 18 to 30 inches in length, the Arizona ridge-nosed rattlesnake is a relatively small snake.

©Matt Jeppson/

The Arizona ridge-nosed rattlesnake lives in south-central Arizona. This species can mostly be found around the “sky island,” the point where Arizona meets Mexico. Arizona’s Santa Rita and Huachuca Mountains have damp pine-oak valleys that are home to the ridge-nosed rattlesnake. The distinct white facial stripes and the ridge down each side of the nose set this species apart.

Despite being well-camouflaged, it will typically try to crawl away quickly if spotted rather than put up a fight. There have been no reported cases of this snake’s bite killing a human, and its venom does not seem particularly strong. The species was found in 1905, but it wasn’t until 1986 that it was named the state’s official reptile. Averaging just 18 to 30 inches in length, the Arizona ridge-nosed rattlesnake is a relatively small snake.

2. Tiger Rattlesnake 

Most Venomous Snakes in the World - Tiger Rattlesnake

The tiger rattlesnake has the tiniest head of any rattlesnake.


The tiger rattlesnake (Crotalus tigris) is a highly venomous pit viper species found in the southwestern United States and northwestern Mexico. The range of the species includes Isla Tiburón in the Gulf of California, southern Sonora, Mexico, central Arizona, and south-central Arizona. The tiger rattlesnake has the tiniest head of any rattlesnake and is easily recognized by its little, spade-shaped head. It also has a base color of gray, blue-gray, buff, lavender, or pink and tiger-like stripes down its body. This snake grows as long as 18 to 36 inches and has extremely poisonous venom.

3. Northern Black-Tailed Rattlesnake

The northern black-tailed rattlesnake ranges from Texas to Arizona and south into the Mexican states of Sonora, Chihuahua, and Coahuila. This rattlesnake is common throughout most of Arizona except for some portions in the northeast. It belongs to the family of black-tailed rattlesnakes. The snake’s body is covered in dark diamond marks, and a dark marking spans its face and eyes. This species is easily recognized by its stunning and vivid color pattern with highly noticeable black patches and by the black tails that appear shortly before the rattles, hence the name “black-tailed” rattlesnakes. Northern black-tailed rattlesnakes can grow as long as 24 to 48 inches. 

4. The Mojave Rattlesnake 

head-on shot of the Mojave rattlesnake

The Mojave Rattlesnake is one of the most deadly snakes in the United States.

©Steve Byland/

The majority of Arizona is home to the Mojave rattlesnake, sometimes known as the Mojave Green. With black diamond-shaped splotches running the length of its back, this species has a bulky body that is gray, yellow-gray, green-gray, or brown. The ones in Arizona’s lower elevations come in various brown tones, frequently with a greenish cast. The species tend to be deeper green at higher altitudes near mountains. One of the easiest ways to identify a Mojave rattlesnake is by alternating white and brown bands on its tail, just before the rattle. This species grows anywhere between 39 to 54 inches long. 

5. The Western Diamondback Rattlesnake 

Western Diamondback rattlesnake closeup

Western diamondback rattlesnakes are large pitvipers.

©Audrey Snider-Bell/

The Western Diamondback Rattlesnake is widespread throughout Arizona, although it is most commonly found in southwest desert areas. It can also be discovered all over the southwest United States and northern Mexico. Given that the species is well-known, mostly for its aggressive nature, it is likely to blame for many snakebite fatalities in northern Mexico and the United States.

It is usually only out during early mornings and late afternoons when the temperature is not as hot, or at night when it hunts for food. The color pattern generally consists of a dusty-looking gray-brown ground color. Some of them have a lighter shade of pink, but they all have diamond markings across their skin. Western diamondback rattlesnakes hold the record for the longest rattlesnakes in Arizona, growing as long as 3 to 6 feet. 

What is The Largest Rattlesnake in Arizona?

As mentioned earlier, there are over 15 different rattlesnake species in Arizona, some of which are not mentioned here. While some do not, others tend to get quite long. Of all the rattlesnakes in Arizona, the largest is still the western diamondback rattlesnake. This species usually grows as long as 3 to 5 feet, but the longest individual is around 6 feet long, making it the longest rattlesnake in Arizona.

Are All Rattlesnakes Venomous?

In North America, rattlesnakes are some of the most dangerous snakes due to their lethal venom. However, the likelihood of being bitten by a rattlesnake is quite remote. Just behind their eyes, rattlesnakes have venom glands, particularly specialized salivary glands. Only 60 to 80 percent of rattlesnake bites contain venom, and if injected into a human, it is only life-threatening if there is a delay in receiving medical care.

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About the Author

For six years, I have worked as a professional writer and editor for books, blogs, and websites, with a particular focus on animals, tech, and finance. When I'm not working, I enjoy playing video games with friends.

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