19 Types of Snakes in Pennsylvania: Complete Identification Guide with Photos

Most people encounter snakes during outdoor activities and immediately wonder: “Is this dangerous?”

The good news is that of the 19 types of snakes in Pennsylvania covered in this guide, only three species pose any real threat to humans.

Understanding these remarkable reptiles transforms fear into fascination while keeping you safe during your outdoor adventures.

You’ll discover comprehensive identification details for these 19 snake species, from the tiny Eastern worm snake to the impressive timber rattlesnake.

This guide provides clear distinguishing features, preferred habitats, and behavioral patterns to help you confidently identify any snake you encounter in the Keystone State.

Pennsylvania’s Snake Diversity: An Overview

Pennsylvania hosts an impressive variety of snake species across its diverse ecosystems.

The state’s mix of forests, wetlands, grasslands, and rocky terrain creates ideal habitats for both common and rare species.

Understanding this diversity helps you appreciate the ecological importance of these often-misunderstood creatures.

Key Facts About Pennsylvania Snakes:

• 19 species covered in this identification guide
• Only 3 species are venomous (all pit vipers)
• Most species are beneficial predators controlling rodent populations
• Habitat loss threatens several species, particularly the Eastern massasauga

Safety Tip: All venomous snakes in Pennsylvania have vertical pupils (like cat eyes) and heat-sensing pits between their eyes and nostrils.

Venomous Snakes in Pennsylvania (3 Species)

Timber Rattlesnake (Crotalus horridus)

The timber rattlesnake represents Pennsylvania’s largest venomous species, reaching lengths up to 60 inches. You’ll recognize this impressive snake by its distinctive diamond-shaped pattern along a yellowish or brownish background, complemented by the characteristic rattle at its tail tip.

These snakes prefer deciduous forests and rocky outcroppings, particularly areas with suitable hibernation sites called hibernacula. During summer months, pregnant females often bask in sunny clearings while males roam wider territories seeking mates.

Identification Features:

• Diamond or chevron pattern down the back
• Obvious rattle (may be broken off in some individuals)
• Heavy-bodied appearance
• Heat-sensing pits between eyes and nostrils

Eastern Copperhead (Agkistrodon contortrix)

The copperhead claims the title as Pennsylvania’s most commonly encountered venomous snake. Its copper-colored head and hourglass-shaped crossbands make it relatively easy to identify once you know what to look for.

These adaptable snakes thrive in various habitats including rocky hillsides, abandoned foundations, and forest edges. Copperheads are ambush predators that remain motionless for extended periods, relying on their excellent camouflage to avoid detection.

Identification Features:

• Copper or reddish-brown head
• Hourglass or “Hershey’s Kiss” shaped crossbands
• Thick, heavy body
• Vertical pupils and heat-sensing pits

Eastern Massasauga (Sistrurus catenatus) – Very Rare

Pennsylvania’s rarest venomous snake, the Eastern massasauga, exists in extremely limited populations. This small rattlesnake prefers wet meadows, marshes, and swampy areas, making it quite different from its timber rattlesnake cousin.

The massasauga’s conservation status makes encounters extremely unlikely, but you should still know how to identify this protected species. Its smaller size and preference for wetland habitats distinguish it from other rattlesnakes.

Identification Features:

• Small rattle (often sounds like a buzzing insect)
• Gray or brownish background with darker blotches
• Smaller than timber rattlesnake (18-30 inches)
• Found only in wetland areas

Conservation Note: The Eastern massasauga is a candidate for federal protection. Never harm or relocate these rare snakes – contact wildlife authorities if encountered.

Large Non-Venomous Snakes (4 Species)

Eastern Rat Snake (Pantherophis alleghaniensis)

The Eastern rat snake ranks among Pennsylvania’s largest non-venomous species, often reaching 6 feet in length. These impressive climbers excel at controlling rodent populations around farms and residential areas, making them valuable allies for property owners.

Adult rat snakes display solid black coloration with white chins, while juveniles show a gray background with darker blotches. Their excellent climbing abilities allow them to access bird nests and rodent hiding spots in trees and structures.

According to the Pennsylvania Fish and Boat Commission, these snakes are particularly beneficial for agricultural areas where they help control crop-damaging rodents.

Identification Features:

• Large size (4-6 feet average)
• Solid black adults with white chin
• Excellent climbing ability
• Rectangular body cross-section when threatened

Black Racer (Coluber constrictor)

The black racer deserves recognition as one of Pennsylvania’s fastest snakes, capable of moving at impressive speeds when threatened. Unlike many snakes that freeze when approached, racers typically flee quickly, earning their common name.

These sleek snakes prefer open areas including fields, forest edges, and rocky slopes. Their speed and agility make them effective hunters of small mammals, birds, and other snakes.

Identification Features:

• Solid black or dark brown coloration
• White chin and throat
• Slender build compared to rat snakes
• Very fast movement when disturbed

Northern Black Racer (Coluber constrictor constrictor)

The Northern black racer represents a subspecies of the black racer with subtle differences in range and characteristics. These snakes share the speed and hunting prowess of their southern cousins while adapting to Pennsylvania’s northern climate.

Expert herpetologists from Wildlife Help note that distinguishing between black racer subspecies requires careful examination of scale counts and geographic location.

Identification Features:

• Similar to black racer in appearance
• Slightly different scale arrangements
• Northern range distribution
• Fast-moving and alert behavior

Eastern Hognose Snake (Heterodon platirhinos)

The Eastern hognose snake wins the award for best actor among Pennsylvania’s snake species. When threatened, these dramatic performers flatten their necks like cobras, hiss loudly, and may even play dead by rolling onto their backs with mouths agape.

Despite their theatrical defensive displays, hognose snakes are completely harmless to humans. They specialize in eating toads and use their upturned snouts to dig prey from sandy soils.

Identification Features:

• Upturned, pig-like snout
• Highly variable coloration (yellow, brown, gray, or reddish)
• Dramatic defensive displays
• Stocky build with keeled scales

Water-Associated Snakes (3 Species)

Northern Water Snake (Nerodia sipedon)

The Northern water snake frequently faces misidentification as a venomous cottonmouth, despite cottonmouths not occurring in Pennsylvania. These semi-aquatic hunters spend considerable time in and around water bodies throughout the state.

Water snakes display variable brown and gray banding patterns that help them blend with rocky shorelines and submerged logs. Their aggressive defensive behavior when handled often reinforces mistaken venomous snake identifications.

Wildlife experts at Snake Snap emphasize that water snakes have round pupils and lack the heat-sensing pits found on venomous species.

Identification Features:

• Brown and gray banded pattern
• Round pupils (not vertical slits)
• Flattened tail for swimming
• Often seen basking on logs or rocks near water

Queen Snake (Regina septemvittata)

The Queen snake represents Pennsylvania’s most specialized aquatic species, feeding almost exclusively on freshly molted crayfish. This dietary specialization makes them excellent indicators of healthy aquatic ecosystems.

These slender snakes prefer clean, rocky streams where crayfish populations thrive. Their olive-brown coloration with yellowish stripes provides excellent camouflage among streambed rocks and vegetation.

Identification Features:

• Three light stripes on olive-brown background
• Strongly keeled scales
• Found exclusively near clean streams
• Relatively small size (15-24 inches)

Eastern Ribbon Snake (Thamnophis sauritus)

The Eastern ribbon snake closely resembles the common garter snake but displays distinct differences in proportions and habitat preferences. These graceful snakes prefer wetland edges and move with flowing, undulating motions.

Ribbon snakes have proportionally longer tails than garter snakes and show more pronounced stripe patterns. They rarely venture far from water sources and feed primarily on amphibians and small fish.

Identification Features:

• Three bright yellow stripes on dark background
• Very long tail (about 1/3 of total length)
• Slender build compared to garter snakes
• Always found near water

Common Terrestrial Snakes (5 Species)

Eastern Garter Snake (Thamnophis sirtalis)

The Eastern garter snake claims the title as Pennsylvania’s most commonly encountered snake species. These adaptable reptiles thrive in diverse habitats from suburban gardens to wild meadows, making them familiar to most outdoor enthusiasts.

Garter snakes display remarkable color variation, ranging from nearly black individuals to bright specimens with vivid yellow stripes. Their tolerance for cool temperatures allows them to remain active later in the season than most other species.

Research from the Pennsylvania Amphibian and Reptile Survey indicates that garter snakes play crucial roles in controlling slug and earthworm populations in agricultural areas.

Identification Features:

• Three longitudinal stripes (usually yellow)
• Highly variable background coloration
• Relatively short tail compared to ribbon snakes
• Often found in gardens and yards

Eastern Milk Snake (Lampropeltis triangulum)

The Eastern milk snake frequently suffers from mistaken identity, with many people confusing these harmless constrictors with venomous copperheads. Understanding the key differences prevents unnecessary fear and potential harm to beneficial snakes.

Milk snakes display red or brown blotches outlined in black on a gray or tan background. Their “Y” or “V” shaped head marking provides a distinctive identification feature absent in venomous species.

Identification Features:

• Red or brown blotches with black borders
• “Y” shaped marking on head
• Smooth scales (not keeled)
• Active primarily at night

Dekay’s Brown Snake (Storeria dekayi)

Dekay’s brown snake represents one of Pennsylvania’s most overlooked species due to its small size and secretive nature. These tiny serpents rarely exceed 12 inches in length but play important roles in controlling invertebrate populations.

Despite their common name, these snakes display variable coloration including gray, reddish-brown, or yellowish hues. A distinctive light stripe down the back often features a series of small dark spots.

Identification Features:

• Very small size (8-12 inches)
• Light dorsal stripe with dark spots
• Brown, gray, or yellowish coloration
• Often found under boards or rocks

Northern Redbelly Snake (Storeria occipitomaculata occipitomaculata)

The Northern redbelly snake shares habitat preferences with Dekay’s brown snake but displays distinctive red or orange belly coloration. These small snakes prefer woodland areas with abundant leaf litter and fallen logs.

Three light spots on the neck provide a reliable identification feature for redbelly snakes. Their secretive nature and small size make encounters relatively uncommon despite stable populations.

Identification Features:

• Bright red or orange belly
• Three light neck spots
• Small size (8-12 inches)
• Brown or gray dorsal coloration

Smooth Green Snake (Opheodrys vernalis)

The smooth green snake stands out as Pennsylvania’s most uniquely colored serpent, displaying brilliant emerald green that provides perfect camouflage among grass and foliage. These small, gentle snakes feed exclusively on insects and spiders.

Unfortunately, smooth green snakes face population declines due to habitat loss and pesticide use. Their specialized diet makes them particularly vulnerable to environmental changes affecting insect populations.

Conservation efforts by Reptile Guide focus on protecting grassland habitats essential for these beautiful snakes.

Identification Features:

• Brilliant green dorsal coloration
• White or yellowish belly
• Very small size (12-16 inches)
• Smooth scales (not keeled)

Small Secretive Snakes (4 Species)

Northern Ring-necked Snake (Diadophis punctatus edwardsii)

The Northern ring-necked snake displays one of nature’s most striking defensive behaviors. When threatened, these small snakes coil their tails to display bright orange or red undersides while hiding their heads beneath their bodies.

Ring-necked snakes prefer moist woodland areas with abundant cover objects like rocks, logs, and leaf litter. Their diet consists primarily of small salamanders, earthworms, and slug species.

Identification Features:

• Distinctive orange or yellow neck ring
• Blue-gray or olive dorsal coloration
• Bright orange belly with black spots
• Small, slender build (10-15 inches)

Eastern Worm Snake (Carphophis amoenus amoenus)

The Eastern worm snake earns its name through remarkable resemblance to large earthworms. These diminutive serpents spend most of their lives underground, emerging primarily during humid conditions or after heavy rains.

Worm snakes represent Pennsylvania’s smallest snake species, rarely exceeding 8 inches in total length. Their specialized lifestyle involves hunting earthworms and soft-bodied invertebrates in soil layers.

Identification Features:

• Extremely small size (4-8 inches)
• Brown dorsal surface
• Pink or salmon-colored belly
• Smooth, shiny scales

Smooth Earth Snake (Virginia valeriae)

The smooth earth snake lives up to its name through secretive, fossorial habits that keep it hidden beneath surface objects for most of its life. These small constrictors feed primarily on earthworms and soft-bodied insects.

Earth snakes display remarkable adaptability to human-modified landscapes, often thriving in suburban areas where suitable cover objects exist. Their small size and gentle nature make them ideal for educational programs.

According to wildlife biologists at WorldAtlas, earth snakes serve as important indicators of soil ecosystem health.

Identification Features:

• Small size (7-10 inches)
• Brown or gray coloration
• Smooth scales
• Light-colored belly

Mountain Earth Snake (Virginia valeriae pulchra)

The Mountain earth snake represents a subspecies of the smooth earth snake adapted to higher elevation habitats. These snakes prefer rocky, mountainous terrain where they hunt invertebrates beneath stones and logs.

Distinguishing mountain earth snakes from their lowland cousins requires careful examination of scale characteristics and geographic location. Both subspecies share similar ecological roles and behaviors.

Identification Features:

• Similar to smooth earth snake
• Preference for mountainous habitats
• Slightly different scale arrangements
• Same small size and secretive behavior

Snake Safety and Identification Tips

Understanding proper snake identification techniques protects both you and these beneficial reptiles. Most snake encounters result from mutual surprise, making calm observation your best approach to safe identification.

Quick Identification Checklist

Venomous Snake Indicators:

1. Vertical, cat-like pupils
2. Heat-sensing pits between eyes and nostrils
3. Triangular head shape
4. Thick, heavy body

Safe Observation Guidelines:

• Maintain at least 6 feet distance
• Never attempt to handle unknown snakes
• Use binoculars for detailed observation
• Take photos from safe distances

What to Do if You Encounter a Snake

Most snake encounters end peacefully when you follow basic safety protocols. Snakes typically avoid human contact and will retreat when given escape routes.

Recommended Actions:

1. Stop and slowly back away – Sudden movements trigger defensive responses
2. Give the snake space – Most species will leave the area voluntarily
3. Never attempt capture – Even non-venomous snakes can deliver painful bites
4. Contact professionals – Wildlife control services handle problem situations

Emergency Information: If bitten by any snake in Pennsylvania, seek immediate medical attention. While most bites come from non-venomous species, proper wound care prevents secondary infections.

Seasonal Snake Activity Patterns

Understanding when and where you’re most likely to encounter different snake species helps you prepare for outdoor activities throughout the year.

Spring Activity (March-May):

• Snakes emerge from hibernation sites
• Increased movement as they search for food
• Mating behaviors make some species more visible
• Cool mornings may find snakes basking in sunny locations

Summer Activity (June-August):

• Peak activity periods during dawn and dusk
• Venomous species may be more defensive during breeding season
• Water snakes become highly active around streams and ponds
• Young snakes appear in late summer

Fall Activity (September-November):

• Snakes prepare for hibernation by feeding intensively
• Movement toward winter den sites increases encounters
• Cool weather may make snakes sluggish
• Last opportunity to observe many species before winter

Conservation and Ecological Importance

Pennsylvania’s snake species face numerous conservation challenges including habitat loss, road mortality, and intentional killing due to fear and misunderstanding. These remarkable predators provide essential ecosystem services that benefit both natural environments and human communities.

Ecological Benefits of Snakes

Rodent Control: A single rat snake can consume dozens of rodents annually, providing natural pest control worth hundreds of dollars in agricultural settings.

Disease Prevention: By controlling rodent populations, snakes reduce disease transmission risks including Lyme disease and hantavirus.

Ecosystem Balance: Snakes occupy crucial positions in food webs, serving as both predators and prey species.

Conservation Challenges

Habitat Fragmentation: Road construction and development fragment snake habitats, leading to isolated populations and increased road mortality.

Climate Change: Shifting temperature and precipitation patterns affect snake distribution and breeding success.

Human Persecution: Fear-based killing remains a significant threat to snake populations throughout Pennsylvania.

How You Can Help

Supporting snake conservation requires both individual actions and community education efforts:

• Learn identification skills to distinguish venomous from harmless species
• Create snake-friendly habitats by maintaining brush piles and rock walls
• Drive carefully during snake season to reduce road mortality
• Support conservation organizations working to protect snake habitats
• Educate others about the ecological importance of snakes

Conclusion

Pennsylvania’s 19 snake species represent a fascinating array of adaptations and ecological roles. From the tiny worm snake hidden beneath your garden stones to the impressive timber rattlesnake in remote mountain forests, each species contributes to the state’s rich biodiversity.

Understanding these remarkable reptiles transforms fear into appreciation while promoting coexistence between humans and wildlife. By learning proper identification techniques and respecting snake habitats, you can safely enjoy Pennsylvania’s outdoors while supporting conservation efforts for future generations.

Remember that snake encounters offer opportunities to observe some of nature’s most efficient predators. With proper knowledge and respect, you can appreciate these ancient survivors that have called Pennsylvania home for thousands of years.

Whether you’re hiking mountain trails, exploring wetlands, or working in your garden, this identification guide helps you recognize the snakes you may encounter throughout the Keystone State. Armed with knowledge and respect, you can coexist safely with these beneficial and beautiful creatures.