19 Types of SNAKES That Live in Wisconsin! (ID Guide)

There are A LOT of snakes in Wisconsin!

And what’s interesting is that they are all incredibly unique and have adapted to fill many habitats and niches.

You’ll see that the snakes that live in Wisconsin are very different from each other.

For example, some species are venomous, while others use constriction to immobilize their prey. Or the fact that certain snakes are rarely seen because they spend most of their time underground, but others are comfortable living EXTREMELY close to humans.

Today, you’re going to learn about the 19 types of snakes in Wisconsin!

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#1. Timber Rattlesnake

• Crotalus horridus

Identifying Characteristics:

• Adults typically range from 30 to 60 inches in length.
• Coloration is variable and generally ranges from yellowish-brown to gray to almost black. Look for dark brown or black crossbands on their back.
• Heavy-bodied with characteristic rattle on the tail.

The Timber Rattlesnake, also known as the Canebrake Rattlesnake, is found in a wide variety of habitats in southwest Wisconsin. Look for these venomous snakes in lowland thickets, high areas around rivers and flood plains, agricultural areas, deciduous forests, and coniferous forests.

Timber Rattlesnake Range Map

Credit: Virginia Herpetological Society

These snakes are ambush predators, waiting for unsuspecting prey to come within range of their strike. They feed primarily on small mammals but may also consume frogs, birds, and other smaller snakes. Timber Rattlesnakes strike their prey and release them, waiting until their venom has taken effect before eating them.

These venomous snakes are potentially the most dangerous species found in Wisconsin due to their large size, long fangs, and high venom yield. Luckily, Timber Rattlesnakes have a mild disposition and don’t bite often. They typically give plenty of warning by rattling and posturing.

The Timber Rattlesnake played a noteworthy role in U.S. history. Found in the original 13 colonies, it was used as a symbol during the American Revolution. In 1775 it was featured at the center of the “Gadsden Flag.” This yellow flag depicts a coiled and ready-to-strike Timber Rattlesnake and the words “Don’t Tread on Me.”

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#2. Eastern Massasauga

• Sistrurus catenatus

Identifying Characteristics:

• Adults are typically around 2 feet in length.
• Coloration is gray or light brown with darker chocolate-brown blotches on the back and smaller ones on the sides, which feature light edges.
• Thick body, vertical pupils, heat-sensing pits between the eyes and nostrils, and heart-shaped head.
• Being rattlesnakes, look for the rattle at the end of their tail.

These small venomous snakes live primarily in wet habitats in Wisconsin.

The name “Massasauga” actually comes from the Chippewa language and means “great river mouth” which describes their habitat. Look for them in floodplain forests, shrub swamps, low areas along rivers and lakes, wet prairies, moist grasslands, bogs, and marshes. During the summer, they often migrate to drier regions adjacent to these habitats.

Eastern Massasauga Range Map

Unlike other rattlesnakes, the Eastern Massasauga hibernates alone. They frequently hibernate in crayfish burrows but may also use small mammal burrows or spaces under rotting logs or tree roots. Dens must be below the frost line, or they risk freezing to death!

These snakes have cytotoxic venom (poisonous to cells), which destroys tissue, disrupts blood flow, and prevents clotting. But these snakes are secretive, shy, and avoid humans when possible. The only times they bite seem to be when handled or accidentally stepped on!

This venomous snake is listed as threatened, endangered, or a species of concern in all of its range. Historically, these snakes have faced pressure from hunting, and many states had bounties and roundups for them. Today they are still often killed out of fear AND face diminishing wetland habitats.

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#3. Northern Watersnake

• Nerodia sipedon sipedon

Identifying Characteristics:

• Adults range from 24 to 55 inches in length.
• Coloration is pale grey to dark brown with reddish-brown to black bands.
• Large adults become darker with age and appear almost plain black or dark brown.
• Females tend to be larger than males, and coloration is most vivid in juvenile and wet individuals.

This species is the most common watersnake in Wisconsin!

Northern Watersnakes prefer slow-moving or standing water like ponds, lakes, vernal pools, marshes, and slow-moving rivers and streams. They’re most often seen basking on rocks or logs in or near the water.

Northern Watersnake Range Map (Yellow area below)

Credit: Virginia Herpetological Society

These snakes primarily feed on fish and amphibians by hunting along the water’s edge and shallow water during the day. They grab their prey and quickly swallow while it’s still alive!

When disturbed, Northern Watersnakes flee into the water to escape. However, if grabbed or captured, they’re quick to defend themselves. They will release a foul-smelling musk from glands near the base of their tale, flatten their body, and strike the attacker.

While non-venomous, they can deliver a painful bite!

Their saliva contains a mild anticoagulant that can cause bites to bleed, making the injury appear worse. These important defense mechanisms help water snakes survive predators such as raccoons, snapping turtles, foxes, opossums, other snakes, and birds of prey.

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#4. Queen Snake

• Regina septemvittata

Identifying Characteristics:

• Adults are generally around 24 inches in length though individuals up to 36 inches have been reported.
• Coloration is drab brown or olive green with two lighter stripes down the sides.
• The underside is yellow or tan, with four dark stripes that run the length of their belly. No other similar species has this feature!

Queen Snakes prefer moving water and are generally found near streams and rivers with rocky bottoms. They have highly permeable skin, making them susceptible to evaporative water loss. As you can imagine, they are rarely spotted far from water.

Queen Snake Range Map

Credit: Virginia Herpetological Society

Queen Snakes are considered less secretive than many other snakes in Wisconsin.

They are primarily diurnal and can be spotted basking on rocks, overhanging branches, or vegetation near the water’s edge. They often take refuge under rocks along the edges of streams. If you’re lucky, you may see them swimming.

Queen Snakes are specialist predators that primarily feed on crayfish. They almost exclusively prey on newly molted crayfish, which have soft bodies and can’t use their pinchers yet. They hunt by probing under rocks and other submerged objects for crayfish.

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#5. Eastern Garter Snake

• Thamnophis sirtalis sirtalis

Identifying Characteristics:

• Adults typically range from 18 to 26 inches in length.
• Coloration varies and can be mixtures of green, brown, or black. Look for a distinct yellow or whitish stripe down the center of their back.
• Some individuals may exhibit a checkered body pattern.
• Subspecies of the Common Garter Snake.

Eastern Garter Snakes are common and easy to locate in Wisconsin!

In fact, they are typically the snake species that people come across the most. They’re well-adapted to living around people and can often be found in city parks, farmland, cemeteries, and suburban lawns and gardens. Though not required, they prefer grassy environments near freshwater sources such as ponds, lakes, ditches, and streams.

Look for these snakes in Wisconsin basking in the sun in grassy areas near cover.

Eastern Garter Snakes protect themselves when they are cornered or feel threatened. For example, if you capture or continually disturb one, it will defecate and release a foul-smelling musk from its glands. It’s also common for them to bite as a last resort!

The Eastern Garter Snake most commonly preys on toads, frogs, slugs, salamanders, fish, and worms. However, they are very opportunistic and will eat other insects and small animals they can overpower. They’re active during both the day and night, depending on the temperature.

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#6. Western Ribbon Snake

• Thamnophis proximus

Identifying Characteristics:

• Adults range from 17 to 50 inches in length. A slender snake with a long tail!
• Coloration is blackish, brown, or olive with three light-colored stripes; one down the back and one down each side.
• The sides and top of the head are dark, and the upper lip is whitish.

Did you see a slender snake in Wisconsin with a long tail?

If so, it was probably a Western Ribbon Snake! This semi-aquatic species is rarely found far from a water source. They typically occupy brush-heavy areas around streams, lakes, ponds, and other water bodies. You may also spot them basking on rocks, flat vegetation, and dry sandy areas near water.

The Western Ribbon Snake has an incredible, unique hunting technique. As they move over land, they make quick, light thrusts of their head and upper body in different directions in sequences of three. It’s similar to a strike, but with their mouth closed. This action disturbs resting frogs, which alerts the garter snake to their location. From there, this snake uses its superior speed to catch its prey.

When they feel threatened, they flee into the water or hide in thick brush. Their coloration provides superb camouflage in dense, brushier areas. If grabbed, Western Ribbon Snakes rarely bite but will thrash around, defecate, and release musk from their anal glands. This species can also shed its tail to escape, but unfortunately, it doesn’t regenerate like some lizard species.

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#7. Plains Garter Snake

• Thamnophis radix

Identifying Characteristics:

• Adults average 36 inches in length.
• Coloration is gray-green with a distinctive orange stripe down the back and a greenish-yellow stripe down each side.
• Distinct light yellow spots on the very top of the head!

Plains Garter Snakes are almost always found in Wisconsin in prairies and grasslands near freshwater sources. They have a fairly large population and adapt well to human-modified landscapes. You may spot them near abandoned buildings, trash heaps, or vacant lots.

This species is considered one of the most cold-tolerant of all snakes! In fact, they will even come out of hibernation on warmer winter days.

Plains Garter Snakes feed primarily on earthworms, slugs, and small amphibians. However, they have also been observed preying on small mammals and birds, including the Eastern Meadowlark and Bank Swallow.

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#8. Eastern Milksnake

• Lampropeltis triangulum triangulum

Identifying Characteristics:

• Adults typically range from 24 to 36 inches in length.
• Coloration is tan or gray with 3 to 5 rows of reddish-brown, black-edged blotches.
• Look for a gray or tan Y- or V-shaped mark near the rear of the head.

Eastern Milksnakes get their unique name from an old myth that they milked cows since they’re commonly found in barns! Obviously, this isn’t true. Instead, their presence inside barns is likely due to the high number of mice, some of their favorite prey.

Eastern Milksnake Range Map

A member of the kingsnake family, Eastern Milksnakes occupy a wide variety of habitats in Wisconsin, including fields, woodlands, agricultural areas, and rocky outcrops. These beautiful snakes are somewhat secretive and spend much of their time beneath the ground. You may be able to find one underneath rocks, logs, boards, and other debris.

The Eastern Milksnake prefers to feed on small mammals such as mice and shrews. However, they’ll also consume various types of prey, including birds and bird eggs, lizards, snakes, amphibians, fish, earthworms, slugs, insects, and carrion.

Like other individuals in the kingsnake family, they will prey on venomous pit vipers. So how do they combat the venom? Interestingly, their blood contains venom-neutralizing properties!

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#9. Gray Ratsnake

• Pantherophis spiloides

Identifying Characteristics:

• Adults range from 42 to 72 inches in length though individuals up to 101 inches have been recorded.
• Coloration varies. Most Gray Ratsnakes are typically completely black.
• There may be red, white, or yellow flecking on the scales.

Look for Gray Ratsnakes in southwest Wisconsin in trees!

They are excellent climbers and often hunt and spend time in trees. Growing up, I used to see them all the time in a large walnut tree in our backyard! They occupy various habitats, including pinelands, stream banks, swamps, marshes, prairies, and agricultural areas.

They’re also spotted near barns and old buildings since these places provide them access to their favorite food, which is rodents.

Like other rat snakes, this species is an active hunter and a powerful constrictor. Adults typically feed on small mammals, birds, bird eggs, lizards, and frogs. They suffocate larger prey using their strong coils but often swallow smaller prey immediately.

If disturbed, Gray Ratsnakes either flee for cover or remain motionless in an attempt to avoid detection using their excellent camouflage. They may also vibrate their tail, producing a rattlesnake-like sound in dry leaf litter. Finally, when they feel cornered or are grabbed, these snakes will strike their attacker as a last resort.

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#10. Smooth Greensnake

• Opheodrys vernalis

Identifying Characteristics:

• Adults are SLENDER and typically range from 14 to 20 inches in length.
• Coloration is uniformly light green with a yellow or white underside and a red tongue with a black tip.
• Juveniles may be olive-green, blue-gray, or even brown until they shed their skin for the first time.

Also called Grass Snakes, these bright green snakes can be found in marshes, meadows, pastures, savannas, open woods, and along stream and lake edges. They prefer moist areas near permanent water sources.

They prey almost exclusively on insects and spiders and don’t use constriction; instead quickly striking and swallowing their prey alive.

Smooth Greensnakes hibernate during the winter in Wisconsin, seeking shelter in old mammal burrows and abandoned anthills. They often hibernate communally with other small snakes. They emerge in the spring, typically in April, and are active until October.

Smooth Greensnakes rely on their EXCELLENT camouflage to avoid predators. They’re also agile and can flee quickly if they must.

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#11. Bullsnake

• Pituophis catenifer sayi

Identifying Characteristics:

• Adults are large and typically range from 4 to 6 feet in length.
• Coloration is yellow, beige, or light brown with large brown, black, or reddish blotching on the back and three sets of small blotches on the sides.
• Blotches may appear like bands near the end of the tail, and the underside is yellowish with black spots.

Bullsnakes are often seen in Wisconsin in areas with high rodent populations.

You can find them in fields, grasslands, forest edges, savannas, and brushlands with sandy soils.

Bullsnakes are fast and can actively pursue prey in loose soil. They even use their prominent rostral (nose scale) to dig! Once they’ve captured their prey, they use their strong body to coil around and constrict their prey.

Despite being nonvenomous, these snakes act aggressively toward any threats. They often lift the front half of their body, hiss, and lunge at their attacker until they feel they can retreat.

Interestingly, their hissing can sound like a rattle! (see below!)

To accomplish this, the snake forces air through an extension of the windpipe, which has a piece of cartilage called an epiglottis that flaps back and forth, sounding very similar to a rattlesnake.

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#12. Eastern Hog-nosed Snake

• Heterodon platirhinos

Identifying Characteristics:

• Adults typically range from 20 to 30 inches in length.
• Coloration can be yellow, gray, brown, black, olive, or orange, often with darker blotches or spots down its side and back, though solid gray and black individuals are fairly common.
• Thick-bodied, broad, triangle-shaped heads, and an upturned snout.

Eastern Hog-nosed Snakes prefer areas in Wisconsin with sandy soil.

Here’s why:

Eastern Hog-nosed Snakes primarily prey on toads and use their upturned snout to dig for them in their burrows. They also have enlarged teeth at the rear of the upper jaw that they use to puncture and deflate toads that puff up when threatened. These snakes also have large adrenal glands, which secrete large amounts of hormones to counteract the toad’s potent skin poison!

When disturbed, Eastern Hog-nosed Snakes lift their head off the ground and flatten their neck like a cobra! They may also hiss and false strike with a closed mouth.

If this display fails to scare off a predator, then the snake will play dead. They’ll roll onto their back, let their tongue hang out, and emit musk from glands near the base of their tail. Interestingly, when the threat has left, the snake will right itself and continue as normal. 🙂

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#13. Dekay’s Brownsnake

• Storeria dekayi

Identifying Characteristics:

• Adults typically range from 6 to 13 inches in length.
• Coloration is light brown or gray to dark brown or black with two rows of dark spots down the back, which are sometimes linked.
• A dark streak down the head and may have a light stripe down the center of the back.

Dekay’s Brownsnakes occupy various terrestrial habitats as long as there’s plenty of cover available such as rocks, logs, boards, and all sorts of trash and organic debris. They’re often found in backyards and gardens under objects.

These secretive, nocturnal snakes hunt during the evening and night, feeding primarily on slugs and earthworms. However, they’ve also been known to consume snails, insects, insect larvae, small tree frogs, tadpoles, frog eggs, spiders, and fish. Prey is typically grabbed and quickly swallowed alive.

These docile snakes usually don’t bite in defense. Instead, if captured, they often squirm vigorously or flatten their bodies and may release foul-smelling musk from glands near the base of their tail.

This species is considered common in most of its range and is not a major conservation concern. It adapts well to human development and has a reputation as a “city snake.” However, pesticide usage and clean-up of cover objects may reduce their populations in urban areas by reducing their habitat and food source.

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#14. Chicago Garter Snake

• Thamnophis sirtalis semifasciatus

Identifying Characteristics:

• Adults reach up to 39 inches in length.
• Coloration is dark brown or black with yellowish stripes down their back and sides.
• The stripes on their sides break into dashed lines near the head.
• The Chicago Garter Snake is a subspecies of the Common Garter Snake.

You’re most likely to find the Chicago Garter Snake in forest and edge habitats. But interestingly, they are only found in the region that surrounds the city of Chicago!

They prefer areas near freshwater sources and can be spotted basking in open areas. These garter snakes are especially cold-tolerant and may even leave hibernation to bask on warm winter days.

Chicago Garter Snakes are similar in behavior and appearance to Eastern Garter Snakes, and both are subspecies of the Common Garter Snake. The main difference is in their appearance. The yellow side stripes on Chicago Garter Snakes are broken into dashed lines near the head.

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#15. Butler’s Garter Snake

• Thamnophis butleri

Identifying Characteristics:

• Adults are slender and range from 15 to 20 inches in length.
• Coloration ranges from olive-brown to black with three yellow to orange stripes, one down the back and one down each side.
• Two rows of dark spots may be visible between the back and side stripes, and the head is usually small.

This snake looks almost identical to an Eastern Garter Snake in Wisconsin.

So how do you tell the difference?

What’s unique to Butler’s Garter Snakes is the placement of their side stripes! Technically speaking, they are centered on the third scale row up from the large, elongated scales on the underside of the body. The side stripes also overlap the adjacent second and fourth scale rows.

But unless you’re a herpetologist or want to inspect a snake closely, this probably means nothing to you. For the rest of us, their head is typically a bit small compared to other garter snakes. In addition, when they are threatened, instead of fleeing, they tend to thrash around in place.

This species is considered endangered in parts of its range. Industrial development of agricultural land has caused significant habitat loss and degradation in their range. If you want to find one, look in moist grassy habitats, typically under cover objects like rocks, logs, boards, and other debris.

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#16. Eastern Foxsnake

• Pantherophis vulpinus

Identifying Characteristics:

• Adults range from 36 to 72 inches in length.
• Coloration is light golden brown, yellow, or bronze with dark brown or reddish-brown blotches down the back and alternating spots down the side.
• Look for a short, flattened snout.

Eastern Foxsnakes are most often found in Wisconsin in grasslands, prairies, and farming areas. They much prefer wet areas as opposed to dry and are typically spotted on the ground. But don’t be surprised if you see one of these snakes in a tree, as they are strong, agile climbers.

These snakes are typically diurnal, but they may hunt at night during extremely hot weather. They often hide under rocks, logs, or in burrows to regulate their temperature. During the winter, they hibernate below the frost line in underground burrows.

Foxsnake Range Map

Eastern and Western Foxsnakes are closely related and look the same. In the past, they were even considered the same species before eventually being split apart. The best way to determine the correct species is by location, as they are divided by the Mississippi River.

If disturbed, Eastern Foxsnakes coil and vibrate their tail, producing a rattlesnake-like sound in dry leaves. If grabbed, they will often release a foul-smelling musk which is thought to smell like a Red Fox, giving them their name.

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#17. Red-bellied Snake

• Storeria occipitomaculata

Identifying Characteristics:  

• A small woodland species that grows between 10 to 25 cm (4-10 in) long.
• Colors vary from orange, gray, black, and brown.
• Their bright red or orange belly stands out from other species.   

This species is probably the “cutest” snake in Wisconsin!

Red-bellied Snakes are small, docile, and have a bright red belly, which makes them VERY easy to identify.

Look for them under logs and leaf litter. They are also commonly found burrowed inside abandoned ant mounds. They are typically diurnal but can be hard to find due to their secretive nature.

Red-belled Snake Range Map

The colors represent the different subspecies of Storeria occipitomaculata.

Red-bellied Snakes have a unique behavior called “lip-curling,” where they curl their lips upward and flick their tongue when eating or feeling threatened. This behavior helps them catch their prey and also scares off potential predators.  

Unfortunately, people often kill this species out of fear. This is incredibly sad because these snakes are harmless and valuable to the ecosystem. In addition to this senseless slaughter, many are killed while crossing roads.   

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#18. North American Racer

• Coluber constrictor

Identifying Characteristics:  

• Adults typically range from 50 to 152 cm (20 to 60 in) in total length  

• The patterns and texture of their skin vary widely among subspecies. However, most are solid-colored and have a lighter-colored underbelly.

True to their name, North American Racers are one of the FASTEST snakes in Wisconsin!

When they get moving, they can speed away at up to 3.5 miles per hour (5.6 kph). These active snakes are curious and have excellent vision. In fact, they are known to raise their heads above the height of the grass to view their surroundings.  

Despite their scientific name (constrictor), North American Racers do not squeeze their prey to death. Instead, they subdue their victim by holding it down with their body. Smaller prey is simply swallowed alive.

North American Racer Range Map

These nonvenomous snakes fight back incredibly hard if they feel threatened or become trapped. You can expect them to bite, thrash, defecate, and release a foul-smelling musk, especially if you try holding one. In addition, racers will try to impersonate rattlesnakes by shaking their tails in dry leaves.  

North American Racers are still abundant in many places. But they face threats as they are losing habitat to urbanization and development. Unfortunately, many people also kill them out of fear, even though they are completely harmless, especially if you leave them alone. 

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#19. Ring-necked Snake

• Diadophis punctatus  

Identifying Characteristics:  

• These snakes are usually solid olive, brown, bluish-gray, or smoky colored. Look for a distinctive yellow or red neckband.   
• The snake’s head color is usually slightly darker than the rest of the body, tending towards black rather than gray or olive.  
• Adults are usually between 25-38 cm (10-15 in) long.  

It can be hard to find these snakes in Wisconsin!

That’s because Ring-necked Snakes are VERY secretive and spend most of their time hiding in areas with lots of cover. In addition, they are nocturnal and rarely seen during the day.

Ring-necked Snake Range Map

The colors represent the different subspecies of Diadophis punctatus.

If you come across one, you may see its unique defense posture. Red-bellied Snakes will curl their tails and expose their bright red-orange bellies when they feel threatened in hopes of scaring you away.

Ring-necked Snakes mostly eat small salamanders, earthworms, and slugs. Not much is known about their population status because they are so hard to find!

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Do you need additional help identifying snakes in Wisconsin?

Try this field guide!

• Peterson Field Guides to Reptiles and Amphibians

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Which of these SNAKES have you seen before in Wisconsin?

Leave a comment below!

Also, if you enjoy this article, make sure to check out these other Wisconsin guides!

• 10 FROGS Found in Wisconsin! (ID Guide)

• 11 Types of TURTLES in Wisconsin! (Both aquatic and land)

• 3 Kinds of LIZARDS That Live in Wisconsin!