Are you wondering what reptiles you can find in Idaho?
This is a great question! Although these reptiles are widespread, they can be difficult to find. Most reptiles, including snakes, turtles, and lizards, are secretive and shy. But observing and finding reptiles is a really fun experience!
Below you will find a list of the most common and interesting reptiles that live in Idaho. In addition, you will find detailed pictures, along with range maps for each species to help with your identification!
7 COMMON Reptiles in Idaho:
#1. Prairie Rattlesnake
- Crotalus viridis
- Adults typically range between 3.3 and 5 feet in length.
- Coloration is highly variable and can be greenish-gray, olive green, greenish-brown, light brown, or yellow. All variations have dark blotches on the body that turn into rings near the tail.
- They have a broad triangular head, elliptical pupils, heat-sensing pits between the eyes and nostrils, and a tail rattle.
Prairie Rattlesnakes have a more varied habitat than many reptiles in northeastern Idaho. These venomous snakes can be found in open prairies, grasslands, semi-desert shrublands, and forested environments. They can even be found at elevations up to 9500 feet!
The Prairie Rattlesnake hibernates during the winter, often in communal dens. These dens are typically rock crevices, caves, or old mammal burrows. Individual snakes return to the same den each winter and migrate up to seven miles to their hunting grounds in the spring.
When they feel threatened Prairie Rattlesnakes may also quietly crawl away to cover. If approached, they coil and rattle their tail as a warning before striking. Their potent venom has both hemotoxic and neurotoxic properties and, although rare, can be fatal to an adult human.
#2. Terrestrial Garter Snake
- Thamnophis elegans
- Adults range from 18 to 41 inches in length.
- Most adults have three yellow, light orange, or white stripes; one down their back and two down their sides.
- Coloration is widely variable. Individuals may be brownish or greenish. Some have red and black spots between the stripes, and occasionally all black individuals are found.
Although they’re common in Idaho, these reptiles can be difficult to identify!
Even trained herpetologists have issues! Its coloration varies widely, and there are believed to be six subspecies, although scientists still debate this.
Terrestrial Garter Snakes occupy various habitats, including both grasslands and forests. They can even be found in mountainous areas up to 13,000 feet above sea level. As the name suggests, they’re primarily found on land. But interestingly, these reptiles are great swimmers!
This species is the only garter snake with a tendency to constrict prey! Most garter snakes grab their prey quickly and just swallow, rubbing their prey against the ground if necessary.
Terrestrial Garter Snakes aren’t aggressive or dangerous, but they possess mildly venomous saliva! It can cause a muscle infection or even kill some muscle tissue. Most bites on humans just cause pain and some swelling.
#3. Western Whiptail
- Aspidoscelis tigris
- 2.5 to 5 inches long from snout to vent (length does not include the tail).
- Body coloring is gray-brown to yellowish, with dark bars or spots that form a web-like pattern.
- Skin folds are present on the neck, making the throat appear wrinkled.
- Rust-colored patches are often present on the sides of the belly.
You can find this reptile in Idaho in sandy, rocky, or firmly packed soil.
Their habitat preferences range from open forest to arid scrubland. Western Whiptails eat other reptiles, scorpions, spiders, termites, and beetles. As you can see, this lizard is anything but picky!
Their physical characteristics and habitats are so varied that there are sixteen distinct subspecies! As you can see in the map above, five subspecies are present throughout the Southwest.
#4. Common Sagebrush Lizard
- Sceloporus graciosus
- 1.9 to 3.5 inches long from snout to vent (length does not include the tail).
- Coloring is gray or brown with a light stripe on each side, a black bar at the shoulder, and blue patches on the belly.
- They have unusually long, almost spidery back claws.
As the name suggests, look for this common reptile in sagebrush in southern Idaho.
Common Sagebrush Lizard Range Map:
Common Sagebrush Lizards eat a wide variety of insects and even scorpions! They hibernate during winter when temperatures drop, and food becomes scarce.
The easiest way to tell if you’ve found a Common Sagebrush Lizard is to look at its belly. The brilliant blue spots on its throat and abdomen are a dead giveaway!
#5. Western Fence Lizard
- Sceloporus occidentalis
- 2.25 to 3.5 inches long from snout to vent (length does not include the tail).
- Black, gray, or dark brown coloring with uneven lighter blotches.
- The sides of the belly are blue, and the backs of the limbs are orange or yellow.
If you see a dark lizard on the ground or a fence, chances are you’ve found a Western Fence Lizard.
They’re the most commonly seen reptile within their range! They aren’t picky about their habitat and live in most ecosystems except the desert.
Western Fence Lizard Range Map:
A fascinating talent of Western Fence Lizards is that they can help lower YOUR risk of Lyme disease.
This spiny lizard’s blood can kill the Lyme Bacteria that many ticks carry! So once an infected tick feeds on the lizard’s blood, they’re cured!
#6. Common Side-Blotched Lizard
- Uta stansburiana
- 1.5 to 2.5 inches long from snout to vent (length does not include the tail).
- Coloring is brownish, occasionally blue-gray, with a blue to black blotch on either side of the chest.
- This species often has white speckles dotting its back in the light color phase.
Common Side-blotched Lizards are comfortable in many different habitats. They’re abundant in their range and easy to find by concentrating on the ground where they spend most of their time.
There are three separate morphs of the male Side-Blotched Lizard, and interestingly, this plays a huge role in the mating habits of this species.
They employ a Rock-Paper-Scissors mechanism, with one morph being dominant over the second (like paper over rock) but not over the third (like scissors cutting paper). This unique mechanism causes a “rotation” of the most common morph each breeding season! The three morphs are pictured below:
#7. Painted Turtle
- Chrysemys picta
- 2.5 to 10 inches long.
- The carapace is low to the ground and generally dark brown or black.
- As the name suggests, they have distinctive yellow, green, and red striping on the carapace, head, and limbs.
The Painted Turtle is one of the most recognizable reptiles in northern Idaho!
Look for its beautiful coloring of bright reds and yellow greens on its shell, limbs, and head. Painted Turtles live near calm, shallow water. They are attracted to areas with plenty of aquatic plants, their primary food source.
Painted Turtle Rangemap:
It’s almost impossible to accurately assess the population of Painted Turtles in Idaho. Many people keep them as pets and then release them into the wild, causing an ever-expanding range and unstable reproduction rates. These released reptiles can also put pressure on natural populations.
In the wild, Painted Turtles can hold their breath for up to 30 hours!
They also can remain dormant in near-freezing water for up to 4 months. This ability is essential when temperatures often go below freezing.
What types of reptiles in Idaho have you seen?
Let us know in the comments!
And if you’re looking for a more comprehensive list of specific reptiles like snakes, lizards, or turtles, check out our ID guides to these fascinating creatures!