Water Snakes of Pennsylvania: Different Species

Snakes of Pennsylvania is home to diverse snake species on land and in the water. Five of the 21 snake species in Pennsylvania are commonly found in and around water sources throughout the state. Learn more about identifying and spotting these five common water snake species in Pennsylvania. Water snakes rely on clean water sources and prefer slow-moving or standing water bodies where they can easily hunt and ambush prey.

Snakes of Pennsylvania

As snakes primarily feed on fish, frogs, and other aquatic animals, water snakes are specially adapted to survive and thrive in marine environments. Their defense mechanisms help water snakes survive predator attacks and flee quickly into the water to escape. While most species are non-venomous, Pennsylvania is home to 3 venomous snake species, including one found commonly near water – the northern copperhead. Learning to identify and safely interact with water snakes is essential for conservation and safety. Read on for an overview of Pennsylvania’s five most common water snake species.

What are Pennsylvania’s most common water snakes?

Pennsylvania is home to a diverse array of snake species that inhabit the land and water. According to the Pennsylvania Amphibian and Reptile Survey (PARS), there are 21 snake species found in the state. Five of these twenty-one species typically situated near or in water.
These include:

  • Northern Water Snake
  • Eastern Ribbon Snake
  • Eastern Garter Snake
  • Northern Rough Green snake
  • Northern Copperhead (venomous)

These five species comprise the most common water snakes found throughout Pennsylvania. Pennsylvania lakes, rivers, streams, and wetlands are home to the five snakes mentioned, as well as additional uncommon snakes, including the northern brown snake and northern ring-necked snake. We describe how to recognize, where to find, and crucial biology and behavior information about these five water snake species below.

How to Identify the Northern Water Snake

Snakes of Pennsylvania

The northern water snake is one of Pennsylvania’s most common species. Growing up to 4.5 feet long, north water snakes have a dark brown or gray back with brown or reddish bands or blotches. Red or black crescents mark the tummy. Northern water snakes live around lakes, rivers, streams, marshes, and ponds statewide. They prefer slow-moving water with muddy bottoms and abundant vegetation or debris for hiding and ambushing prey.

These non-venomous snakes feed on fish, frogs, and other aquatic animals. They need persistent water to survive as semi-aquatic animals. When threatened, northern water snakes will quickly flee into the water and dive beneath the surface or hide in vegetation along the shore.

Where are Pennsylvania ribbon snakes?

Snakes of Pennsylvania

The eastern ribbon snake is a slender, brightly colored snake that inhabits the eastern half of Pennsylvania. Adults reach 16–35 inches long and have three yellow or white stripes running the length of a brown or black body. Their bellies are yellow or greenish-white.

Ribbon snakes are semi-aquatic and found near permanent still or slow-moving water bodies like marshes, ponds, bogs, and streams with muddy bottoms and shoreline vegetation. They like sunny areas and sunbathe in short grasses overhanging the river. These small, non-venomous snakes primarily hunt in the water and prey on amphibians like frogs and salamanders. When threatened, they will quickly dive into the water to escape. Pennsylvania is home to two populations of ribbon snakes, with northern ribbon snakes occurring in the northwestern and east half of the state.

Are Pennsylvania’s Waters Home to Northern Copperhead?

In Pennsylvania, you can see the northern copperhead—one of three poisonous snakes—most often in or around bodies of water like swamps, ponds, and streams. Adults reach 2-3 feet long and have tan, chestnut, or pinkish-tan bodies marked by brown or reddish-brown hourglass-shaped bands. The colors help them camouflage near fallen leaves.

Except for the southeast, northern copperheads are widespread throughout Pennsylvania. Western Pennsylvania has moist woods and forested areas near water where these pit viper snakes live. They are not typically aggressive and prefer to escape rather than bite if given the chance. Bite victims should seek medical assistance immediately.

Where are Pennsylvania garter snakes?

The common eastern garter snake is one of the most abundant and widespread snakes found throughout Pennsylvania. Growing up to 4 feet long, they have a brown or green background color with three yellow or white stripes running the length of their bodies. Some may have red or blue spots between the stripes.

Garter snakes thrive in various habitats near permanent water sources, like streams, marshes, ponds, and lakes. They may be seen basking on rocks, logs, or vegetation near the shore and will quickly flee across the water or dive below the surface when threatened.

These non-venomous snakes feed on fish, frogs, toads, salamanders, and earthworms. They are one of the first snakes to emerge in spring and may be active during the day in cooler weather.

How to Spot the Northern Rough Green Snake

Lastly, the northern rough green snake is a bright green snake inhabiting forests, meadows, and agricultural areas, strongly tied to permanent water sources. Reaching 22-47 inches long, these slender snakes are bright green above with a yellowish or white underside. Unlike other smooth-scaled species, the scales along their bodies create a rough texture.

Rough green snakes hide behind trash along small streams and marshes throughout.
They may also bask on waterside vegetation. When threatened, they flee quickly to the nearest water source to escape predators. These docile, non-venomous snakes prey on insects, spiders, slugs, and other invertebrates. They are diurnal hunters, most active during the day. Loss of wetland habitat threatens some populations in Pennsylvania.

2) Northern rough green snake (Opheodrys aestivus)

In Pennsylvania, the northern fierce green snake could be found in Greene County and Chester County, but nowadays, it can only be found in the latter county.

  • Native to the southeastern US
  • Family: Colubridae
  • Order: Squamata
  • Conservation status: Least concern

The maximum length of the northern rough green snake is 117 cm (3 ft 10 in), although individuals are more commonly found at lengths of around 56–81 cm (1 ft 10 in – 2 ft 8 in). This snake has a slender body, with a tail tapering to a fine tip. Its dorsum is bright green, while the ventral region varies in color from pale green to yellow to cream.

Only Chester County, Pennsylvania, has Opheodrys aestivus. Although there are no current demographic data for the area, it was once in Greene County. Although the overall conservation status of this species is that of least concern, in Pennsylvania, it is critically imperiled, possibly due to the clearance of wooded wetlands and the use of pesticides. This species is semi-aquatic, often found at the margins of lakes, streams, and marshes. Like many other arboreal species, it can reach up to 20 feet. The food hunted by the northern rough green snake is numerous in forest boundaries, which may be why these snakes are frequently found here. Everyday prey items include caterpillars, spiders, grasshoppers, and crickets.


Pennsylvania is home to 5 common species of water snakes that rely on the state’s abundant aquatic habitats to survive. These include the northern water snake, eastern ribbon snake, eastern garter snake, northern rough green snake, and the venomous northern copperhead. Pennsylvania’s ponds, lakes, streams, marshes, and swamps are home to ribbon snakes under 3 feet and north-strong water snakes and copperheads up to 4 feet long. Learning to identify water snakes by sight, behavior, and habitat preferences can foster greater understanding and conservation of these critical but often misunderstood predators that share the state’s waterways with humans. Watching for water snakes basking along shorelines provides opportunities to appreciate the diversity of snake species native to Pennsylvania.

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