Pennsylvania Snakes Identification Guide: All Species & Pics

Having the ability to identify wild snakes in your area is an important skill set to possess.

Knowing whether you’re facing a harmless snake like the Eastern Milk Snake, or a venomous snake like the Eastern Copperhead, can help you avoid a potentially dangerous situation.

There are 21 species of Pennsylvania snakes, three of which are venomous.

This guide will assist you in learning how to identify the most common, most dangerous, and rarest snakes in Pennsylvania.

You’ll discover how to co-exist with wild snakes, what to do if you meet one, and who to contact for emergency advice, snake removal, and additional information.

In Short

  • If you see a snake in the wild, respect its space.
  • Snakes are essential features of the PA ecosystem.
  • All three venomous snake species in the state are pit vipers.
  • The most common snakes in PA are the Eastern Garter Snake, and Northern Watersnake.
  • Most snake bites happen when someone is trying to kill, relocate, or harass a snake in some way.
  • There are three endangered snake species in PA; The Eastern Massasauga, Kirtland’s Snake, and Northern Rough Greensnake.

PA Snake Identification Basics

This guide is only for Pennsylvania snake identification.

Snake appearances often vary based on habitat and geographic location.

Even within populations, there are aberrant snakes (ones that appear different from a typical snake of that species).

Some of the most useful elements to consider when you come across a snake are:

  • Size – If you find a large snake, you can be certain it isn’t an Eastern worm snake, for example. The patterns of a copperhead and an Eastern milk snake may appear similar at a glance, but their size differences help set them apart.
  • Color – A bright green snake, like the smooth green snake, definitely can’t be confused with a timber rattlesnake.
  • Location – Some species live in specialized habitats, and you’ll only find them in particular areas of the state.
  • Pupil shape – All of the venomous species in PA have elliptical-shaped pupils, while the harmless ones have round pupils.

Many snakes have similar patterns and coloration that can be problematic when attempting to identify them.

You’re most likely to correctly ID a snake when incorporating all of these aspects together.

Quickly Identifying Venomous Species

There are three venomous species in Pennsylvania.

Some of them are easy to mistake for one of the many harmless species throughout the state.

Fortunately, Pennsylvania’s most dangerous snakes are closely related and share several distinguishing characteristics.

I’ll cover the best ways to differentiate a harmless snake from a venomous one, and go over each venomous species in detail below.

If you have doubts about a snake’s identity, you should always err on the side of caution.

All Venomous Snakes in Pennsylvania Are Pit Vipers

All three species of venomous snakes in Pennsylvania are members of the Viperidae family.

These venomous pit vipers can be distinguished from harmless species in the state by several mutual characteristics:

  • Elliptical pupils
  • Heat-sensing pits
  • Broad, triangle-shaped heads

These three species have elliptical-shaped pupils, like a cat’s eyes, while all nonvenomous snakes in PA have round pupils.

You’ll also find sensory pits between their eyes and nostrils. These detect heat and assist them in locating prey.

The head of a pit viper is a well-defined triangle shape due to the location of the venom glands on each side.

Some harmless snakes will puff up their head and neck when they feel threatened, which can be deceiving to humans and other predators.

Copperhead snake
The head of a pit viper is shaped like an arrow and is noticeably wider than its neck.

These characteristics are most obvious at close range, so please be cautious when looking for them.

Northern Copperhead

Northern Copperhead Snake on soil
A copperhead’s coloration helps it camouflage seamlessly with the leaf litter and soil of its preferred habitats.

Scientific Name:

Eastern Copperhead Agkistrodon contortrix

Agkistrodon contortrix mokasen Northern Copperhead subspecies

Range:

Statewide except for the northern border of Pennsylvania

Size:

24-36 inches

Description:

Keeled scales

Heavy-bodied

Elliptical pupils on a large triangle-shaped head

Copper brown head and a tan, pinkish-brown, or grayish-brown body

Hourglass or saddle-shaped brown bands down the length of the body

Juveniles have similar coloration as adults, except for yellow or green-tipped tails

Habitat:

Forests, rocky hillsides, open habitats, sometimes near sources of water

Diet:

Mice, birds, lizards, amphibians, insects, and small snakes

Venomous/Non-Venomous:

Venomous

The copperhead is the most common venomous snake in PA.

People often misidentify Northern water snakes and Eastern milk snakes as copperheads.

The most notable difference between these species:

Species

Pupils

Head Shape

Pattern

Northern Copperhead

Elliptical pupils

Triangle head

Hourglass-shaped bands narrow in the center of the back and widen towards the sides, solid copper-colored head

Northern Water Snake

Round pupils

Oval-shaped head (only appears triangular when threatened)

Bands opposite of a copperhead’s, wide in the center and narrow towards the edges, rectangular blotches along the sides, coloration and pattern variable, older adults appear patternless

Eastern Milk Snake

Round pupils

Narrow head

V, U, or Y-shaped mark on top of the head, square-shaped blotches with black borders along the back instead of bands, small blotches along the sides

Timber Rattlesnake

Timber Rattlesnake on top of dead leaves
Rattlesnakes can shake their tails as quickly as 90 times per second!

Scientific Name:

Crotalus horridus

Range:

Statewide except for the western border and southeast corner of Pennsylvania

Size:

36 – 60 inches

The largest venomous species in the state

Description:

Keeled scales

Heavy-bodied

Vertical pupils on a large, triangle-shaped head

Sometimes have a dark stripe from the eye to the corner of the mouth

Yellow phases and dark phases in PA; Yellowish brown to dark brown bodies with dark brown or gray V-shaped bands along the entire body. Tail is solid dark brown, gray, or black with a lighter-colored rattle.

Habitat:

Upland, mature, and young forests

Diet:

Small mammals, birds, frogs, and other snakes

Venomous/Non-Venomous:

Venomous

Eastern Massasauga

Eastern Massasauga underneath dead leaves
The Eastern Massasauga is endangered in the state of Pennsylvania.

Scientific Name:

Sistrurus catenatus catenatus

Range:

Butler, Mercer, and Venango Counties in western Pennsylvania

Size:

18-40 inches

Description:

Elliptical pupils

Small and stocky

Gray or grayish-brown body with keeled scales

Dark line from the eye to the corner of the mouth

Large, dark brown, irregularly shaped blotches down the back and rows of round spots along the sides. The tail has dark rings and a small rattle

Habitat:

Wetlands, wet meadows, and prairies. Found in wet habitats in spring and fall, and dry habitats in summer

Diet:

Small mammals, lizards, frogs, other snakes, and invertebrates

Venomous/Non-Venomous:

Venomous

Snakes Found in Pennsylvania

The Keystone State doesn’t have the highest diversity of snakes, but you’ll still find an impressive variety for its northeastern location.

There are 21 species of snakes found in Pennsylvania, and nearly all of them are nonvenomous.

Let’s discuss the state’s most common species in detail, and discover all of its native snakes.

Most Common Snakes in Pennsylvania

Memorizing all 21 species native to Pennsylvania is a tall order.

It’s more efficient to spend your time focusing on which species you’re most likely to run into.

According to observations on iNaturalist, the six most abundant snake species in the state, from most to least common, are:

  1. Eastern Garter Snake – Thamnophis sirtalis sirtalis
  2. Common Water Snake – Nerodia sipedon
  3. Dekay’s Brown Snake – Storeria dekayi
  4. Ring-necked Snake – Diadophis punctatus
  5. Eastern Rat Snake – Pantherophis alleghaniensis
  6. Milk Snake – Lampropeltis triangulum

Eastern Garter Snake

Eastern Garter Snake on dead leaves
Garter snakes birth live young and typically have 20 to 40 at once to compensate for high mortality rates.

Scientific Name:

Thamnophis sirtalis sirtalis

Range:

Statewide

Size:

20-28 inches

Description:

Round pupils

Keeled scales

Coloration is variable; green, brown, or black

White, tan, yellow, brown, or gray stripes along the spine and sides. The dorsal stripe may be absent

There may be rows of black or red spots between the stripes

Habitat:

Habitat generalists. Often found near sources of water and human homes

Diet:

Amphibians, earthworms, rodents, birds, and fish

Venomous/Non-Venomous:

Non-venomous

Garter snakes’ affinity for suburban gardens has earned them the nickname ‘garden snakes’ in Pennsylvania.

This is a snake species you certainly want to keep around. They’re not aggressive snakes, and they’ll help you keep a healthy garden by eating pests.

Common Water Snake

Water snake on top of rock
Water snakes often bask on rocks, logs, or vegetation.

Scientific Name:

Nerodia sipedon

Northern Water Snake subspecies Nerodia sipedon sipedon

Range:

Statewide

Size:

24-55 inches

Description:

Round pupils

Keeled Scales

Heavy bodied species

Brown, tan, or gray with brown or reddish-brown bands and blotches along the body

Juveniles have more distinct patterns that darken as they age

Habitat:

Near sources of water, such as lakes, ponds, rivers, canals, swamps, and marshes

Diet:

Fish, amphibians, small mammals, birds, and invertebrates

Venomous/Non-Venomous:

Non-venomous

Dekay’s Brownsnake

Dekay's Brownsnake in a branch
Brown snakes often inhabit gardens and parks in urban areas.

Scientific Name:

Storeria dekayi

Northern Brown Snake subspecies Storeria dekayi dekayi

Range:

Western quarter of the state and most of Southeast and Central Pennsylvania

Size:

9-13 inches

Description:

Keeled scales

Round pupils

Light gray, grayish-brown, or dark brown

A lighter dorsal stripe bordered by dark brown or black spots

Habitat:

A variety of habitats, including woodlands, grasslands, marshes, and urban areas

Diet:

Slugs, snails, earthworms, and soft insects

Venomous/Non-Venomous:

Non-venomous

Ring-necked Snake

 Ringneck Snake on ground
When threatened, ring-necked snakes expose their brightly colored bellies to warn predators.

Scientific Name:

Diadophis punctatus

Northern Ring-necked Snake subspecies Diadophis punctatus edwardsii

Range:

Statewide

Size:

12-15 inches

Description:

Round pupils

Smooth scales

Dark gray, blue-gray, or olive-brown

Bright orange or yellow neck ring and ventral scales

Habitat:

A variety of habitats, particularly damp hardwood forests, rocky areas, and fields

The northern ring-necked snake is one of the most common species found in PA homes

Diet:

Earthworms, slugs, and amphibians

Venomous/Non-Venomous:

Non-venomous

Eastern Rat Snake

Eastern rat snake on tree bark
Eastern rat snakes are the largest snakes in Pennsylvania.

Scientific Name:

Pantherophis alleghaniensis

Range:

Statewide

Size:

40 -101 inches

Description:

Round pupils

Slightly keeled scales

Solid black or brown with black blotches

White lips, chin, throat, and ventral scales. Ventral scales have a checkerboard pattern

Juveniles are white or yellow with gray, black, or brown blotches

Habitat:

Farmlands, forests, fields, and meadows

Diet:

Rodents, lizards, frogs, birds, and bird eggs

Venomous/Non-Venomous:

Non-venomous

The eastern rat snake is commonly called a black rat snake in Pennsylvania.

It’s easy to mistake this species for the northern racer (Coluber constrictor), another black snake species found throughout most of the state.

black racer snake on top of dead leaves
There are 11 different subspecies of Eastern Racer in the US, and the northern racer is the only one found in PA.

The northern racer has large, smooth, glossy scales, a prominent eyebrow ridge, and dark gray ventral scales.

Eastern Milksnake

Eastern Milk Snake
The milk snake gets its name from an old myth that it sneaks into barns to drink the milk from cows.

Scientific Name:

Milksnake Lampropeltis triangulum

Eastern Milksnake subspecies Lampropeltis triangulum triangulum

Range:

Statewide

Size:

24-52 inches

Description:

Smooth scales

Small, blunt head with round pupils

A dark V, U, or Y-shaped mark on top of the head

Ventral scales have a checkerboard pattern

Appearance varies. Typically gray, tan, various shades of brown, or red

Large dark brown or reddish-brown blotches outlined in black run down the back and sides

Habitat:

Various habitats, including forests, farmland, rocky hillsides, and urban areas

Diet:

Generalists; rodents, reptiles, amphibians, invertebrates, birds, and bird eggs

Venomous/Non-Venomous:

Non-venomous

Snakes Native to Pennsylvania

All but three snakes of Pennsylvania are Colubrids.

The Colubridae family is the largest and most diverse snake family.

From a tiny pink snake, like the worm snake, to an intimidatingly large snake, like the rat snake, you’ll find a list of all snake species in the state organized by family and genera below.

Colubridae:

Racers

Eastern Racer

Coluber constrictor

Rat Snakes

Eastern Ratsnake

Pantherophis alleghaniensis

Kingsnakes

Milk Snake

Lampropeltis triangulum

Worm Snakes

Eastern Worm Snake

Carphophis amoenus

Water Snakes

Common Water Snake

Nerodia sipedon

Brown Snakes

Red-bellied Snake

Storeria occipitomaculata

DeKay’s Brownsnake

Storeria dekayi

Earth Snakes

Smooth Earth Snake

Virginia valeriae

Mountain Earth Snake

Virginia pulchra

Green Snakes

Rough Green Snake

Opheodrys aestivus

Smooth Green Snake

Opheodrys vernalis

Garter Snakes

Ribbon Snake

Thamnophis sauritus

Common Garter Snake

Thamnophis sirtalis

Short-headed Garter Snake

Thamnophis brachystoma

Crayfish Snakes

Queen Snake

Regina septemvittata

Hognose Snakes

Eastern Hognose Snake

Heterodon platirhinos

Kirtland’s Snakes

Kirtland’s Snake

Clonophis kirtlandii

Ring-necked Snakes

Ring-necked Snake

Diadophis punctatus

Viperidae:

Rattlesnakes

Timber Rattlesnake

Crotalus horridus

Massasaugas

Eastern Massasauga

Sistrurus c. catenatus

American Moccasins

Eastern Copperhead

Agkistrodon contortrix

At-Risk and Endangered Species

There are three species of snakes considered ‘endangered’ in the state of Pennsylvania:

  1. Kirtland’s Snake – The Kirtland’s snake is a small, elusive species that prefer open, wet habitats. It used to inhabit western Pennsylvania, but no one has seen this snake in the state in decades. Its population has declined due to habitat loss.
    Kirtland's Snake coiled with leaves at the bottom
    When threatened, the Kirtland’s Snake flattens its body.
    Image credit: Todd W Pierson via Creativecommons.org
  2. Eastern Massasauga -You can only find these snakes in western PA. They have specific habitat preferences in wetlands near dry fields and meadows. Habitat destruction is the leading cause of their decline.
  3. Northern Rough Greensnake – The northern rough greensnake was never abundant in Pennsylvania, but is now only found in one southeastern county of the state.
Greensnake on a tree
Greensnakes are skilled climbers found in shrubs and trees near water.

There are 11 species of special concern, meaning they’re in danger of becoming threatened due to declining population sizes, specialized habitats, or unnecessary persecution.

Those species include:

  1. Queen Snake
  2. Timber Rattlesnake
  3. Smooth Greensnake
  4. Eastern Wormsnake
  5. Northern Copperhead
  6. Mountain Earthsnake
  7. Northern Ribbonsnake
  8. Common Ribbonsnake
  9. Shorthead Gartersnake
  10. Eastern Hognose Snake
  11. Eastern Smooth Earthsnake

It’s illegal to capture or kill these species.

The only exceptions are the eastern copperhead and timber rattlesnake, which still have restrictions.

What You Need to Know

Snakes aren’t the horrifying creatures they’re made out to be.

They won’t chase or attack you.

Snakes are just as startled by your presence as you are by theirs. They see us as predators, not prey.

Like all wildlife, snakes want to be left alone. They’ll usually give several warning signs before resorting to biting.

Most bites occur when someone is trying to kill, harass, or relocate a snake.

The best way to avoid an unwanted confrontation with a snake is to respect its space.

Coexisting With Pennsylvania Snakes

Snakes play a vital role in Pennsylvania’s ecosystem.

Many animals rely on snakes as a source of food, including birds of prey, foxes, turtles, raccoons, and even other snakes.

They’re also nature’s pest control, helping keep mice, rats, and insect populations in check.

Unless a snake has made its way inside of your home, or you’re in immediate danger, it’s best to put your fears aside and live side-by-side with these marvelous creatures.

Snake Safety

About Venomous Snakes

There are few truly dangerous snakes in Pennsylvania, and venomous bites are extremely rare.

A snake’s venom is primarily used to subdue prey and is only used for protection when the snake is in fear for its life.

Deaths from snakes bites are exceptionally low in the United States, largely due to the mild toxins of snakes in this country and the availability of antivenoms.

If you take extra precautions and leave snakes alone, there’s no need to worry about a bite from these elusive reptiles.

Treading Carefully in Snake Habitat

If you’re spending time in an area known to house snakes, there are several preventative measures you can take to keep you and your loved ones safe.

Most importantly:

  • Watch your step
  • Keep your pets on a leash
  • Stick to paved or worn paths
  • Wear sturdy, tall hiking boots and long pants
  • Be conscious of where you place your hands

Snakes often hide in tall grass or under wood, rocks, and debris.

If You Encounter a Snake

Snakes are generally shy animals and don’t like to be around people.

Occasionally you may find a snake in your yard or even inside your home.

The crucial thing to remember is not to panic.

If the snake is in a location where it doesn’t pose a threat to you or your loved ones, it’s best to leave it alone.

The same goes for snake eggs. In Pennsylvania, it’s illegal to damage or disrupt a reptile’s nest or eggs.

Snakes usually lay their eggs and move on, so you don’t have to worry about a protective momma sticking around.

When to Call for Help

Reach out to a professional wildlife trapper if you feel uncomfortable removing a snake from your home.

If a venomous snake bites you, call 911 or have someone drive you to the nearest emergency room immediately.

Antivenom is most effective when administered within a few hours.

Stay calm and move as little as possible.

Seek emergency veterinary care if a snake bites your pet.

Useful Resources

Penn State Poison Center: 1-800-222-1222

Contact the American Society for the Prevention of Cruelty to Animals (ASPCA) Animal Poison Control Center at 1-888-426-4435 for advice on what to do if a snake bites your pet.

Your regional Pennsylvania Fish and Boat Commission office will relocate venomous species for you.

Visit WildlifeHelp.org for advice on how to deal with snakes in your area.

Report your snake sightings to The Pennsylvania Amphibian and Reptile Survey (PARS) and discover more in-depth information on PA reptiles and amphibians.

Find a professional in your area with this Free Snake Relocation Directory on Facebook.

Related Articles to Pennsylvania Snake Identification

If you’re excited about identifying snakes in the wild, you might be interested in these guides:

Don’t forget to take a look at more snake articles written by reptile pros.

Have you seen these snakes in the wild? Let us know in the comments!

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