Snakes in Pennsylvania
Pennsylvania has 20 snake species on record, each with at least 10 GBIF records in the state, and 8,487 licensed records in all. The most recorded are the common garter snake, the ring-necked snake and the northern water snake. Three of them are venomous.
Rattlesnakes in Pennsylvania
Rattlesnakes: two species are listed for Pennsylvania, with 534 records (6% of the state's snake records). The most recorded is the timber rattlesnake (479), ahead of the eastern massasauga (55).
Observation records of the timber rattlesnake in Pennsylvania run mostly May through August, peaking in July; most licensed records come from Wyoming County, Centre County and Susquehanna County. Most licensed records of the eastern massasauga in Pennsylvania come from Butler County, Venango County and Crawford County.
Copperheads and cottonmouths in Pennsylvania
One species of this group is listed for Pennsylvania: the eastern copperhead, with 261 records (3% of the state's snake records).
Most licensed records of the eastern copperhead in Pennsylvania come from Allegheny County, Westmoreland County and Montgomery County.
Water snakes and swamp snakes in Pennsylvania
Water snakes and swamp snakes: three species are listed for Pennsylvania, with 1,448 records (17% of the state's snake records). The most recorded is the northern water snake (859), ahead of the queen snake (566).
Observation records of the northern water snake in Pennsylvania run mostly April through August, peaking in May; most licensed records come from Allegheny County, Erie County and Westmoreland County. Most licensed records of the queen snake in Pennsylvania come from Allegheny County, Westmoreland County and Washington County.
Garter snakes and ribbon snakes in Pennsylvania
Garter snakes and ribbon snakes dominate the snake record of Pennsylvania: three species and 27% of all records. The most recorded is the common garter snake (1,686), ahead of the shorthead garter snake (523).
Observation records of the common garter snake in Pennsylvania run mostly March through October, peaking in May; most licensed records come from Allegheny County, Erie County and Westmoreland County. Most licensed records of the shorthead garter snake in Pennsylvania come from Warren County, Clarion County and Forest County. Most licensed records of the eastern ribbonsnake in Pennsylvania come from Allegheny County, Crawford County and Erie County.
Rat snakes and corn snakes in Pennsylvania
One species of this group is listed for Pennsylvania: the eastern rat snake, with 358 records (4% of the state's snake records).
Observation records of the eastern rat snake in Pennsylvania run mostly April through September, peaking in June; most licensed records come from Allegheny County, Westmoreland County and Centre County.
Kingsnakes and milksnakes in Pennsylvania
One species of this group is listed for Pennsylvania: the eastern milksnake, with 520 records (6% of the state's snake records).
Observation records of the eastern milksnake in Pennsylvania run mostly April through September, peaking in May; most licensed records come from Allegheny County, Centre County and Crawford County.
Racers, whipsnakes and indigo snakes in Pennsylvania
One species of this group is listed for Pennsylvania: the eastern racer, with 185 records (2% of the state's snake records).
Observation records of the eastern racer in Pennsylvania run mostly April through September, peaking in April; most licensed records come from Allegheny County, Cumberland County and Bucks County.
Hognose snakes in Pennsylvania
One species of this group is listed for Pennsylvania: the eastern hog-nosed snake, with 99 records (1% of the state's snake records).
Most licensed records of the eastern hog-nosed snake in Pennsylvania come from Indiana County, Wyoming County and Pike County.
Green snakes in Pennsylvania
Green snakes are a small part of the snake record here: two species with 2% of records between them. The most recorded is the smooth green snake (210), ahead of the rough greensnake (2).
Most licensed records of the smooth green snake in Pennsylvania come from Potter County, McKean County and Monroe County.
Small woodland and burrowing snakes in Pennsylvania
Small woodland and burrowing snakes dominate the snake record of Pennsylvania: five species and 27% of all records. The most recorded is the ring-necked snake (932), ahead of the DeKay's brown snake (509).
Observation records of the ring-necked snake in Pennsylvania run mostly April through September, peaking in May; most licensed records come from Warren County, Westmoreland County and Potter County. Observation records of the DeKay's brown snake in Pennsylvania run mostly March through November, peaking in May; most licensed records come from Erie County, Montgomery County and Allegheny County. Observation records of the red-bellied snake in Pennsylvania run mostly May through September, peaking in July; most licensed records come from Warren County, Potter County and Forest County.
Where in Pennsylvania are snakes recorded most?
Allegheny County leads with 864 records (10%), followed by Warren County and Westmoreland County; the top five counties hold 31% of the total. 67 of Pennsylvania's 67 counties have at least one licensed snake record.
| # | County | Records | Share |
|---|---|---|---|
| 1 | Allegheny County | 864 | 10.2% |
| 2 | Warren County | 695 | 8.2% |
| 3 | Westmoreland County | 509 | 6.0% |
| 4 | Erie County | 316 | 3.7% |
| 5 | Potter County | 278 | 3.3% |
| 6 | Wyoming County | 275 | 3.2% |
| 7 | Centre County | 239 | 2.8% |
| 8 | Montgomery County | 239 | 2.8% |
| 9 | Venango County | 205 | 2.4% |
| 10 | Forest County | 204 | 2.4% |
| 11 | Butler County | 197 | 2.3% |
| 12 | Crawford County | 193 | 2.3% |
When do snakes come out in Pennsylvania?
Observation records of snakes in Pennsylvania run mostly April through October, peaking in May with 22% of them. December through February together hold under 2% of the records, so snakes in Pennsylvania are rarely recorded in winter. The sharpest rise comes from March to April.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1% | 0% | 4% | 13% | 22% | 19% | 15% | 10% | 9% | 6% | 2% | 0% |
Snakes: Pennsylvania compared with its neighbors
Pennsylvania ranks 27th of 50 states by the number of snake species listed, level with Maryland; Texas leads with 86 species.
Of the six states bordering Pennsylvania, Ohio lists more snake species; Maryland lists as many (Pennsylvania: 20 species; Ohio 25, Maryland 20, New Jersey 18, West Virginia 18, New York 17, Delaware 14).
What snakes are in Pennsylvania? All 20 species
Ranked by licensed records in Pennsylvania. Species with a profile page are linked.
| # | Species | Family | Records | Share |
|---|---|---|---|---|
| 1 | Common garter snake Thamnophis sirtalis | Colubridae | 1,686 | 19.9% |
| 2 | Ring-necked snake Diadophis punctatus | Colubridae | 932 | 11.0% |
| 3 | Northern water snake Nerodia sipedon | Colubridae | 859 | 10.1% |
| 4 | Queen snake Regina septemvittata | Colubridae | 566 | 6.7% |
| 5 | Shorthead garter snake Thamnophis brachystoma | Colubridae | 523 | 6.2% |
| 6 | Eastern milksnake Lampropeltis triangulum | Colubridae | 520 | 6.1% |
| 7 | DeKay's brown snake Storeria dekayi | Colubridae | 509 | 6.0% |
| 8 | Timber rattlesnake venomous Crotalus horridus | Viperidae | 479 | 5.6% |
| 9 | Red-bellied snake Storeria occipitomaculata | Colubridae | 465 | 5.5% |
| 10 | Smooth earth snake Virginia valeriae | Colubridae | 368 | 4.3% |
| 11 | Eastern rat snake Pantherophis alleghaniensis | Colubridae | 358 | 4.2% |
| 12 | Eastern copperhead venomous Agkistrodon contortrix | Viperidae | 261 | 3.1% |
| 13 | Smooth green snake Opheodrys vernalis | Colubridae | 210 | 2.5% |
| 14 | Eastern racer Coluber constrictor | Colubridae | 185 | 2.2% |
| 15 | Eastern ribbonsnake Thamnophis saurita | Colubridae | 103 | 1.2% |
| 16 | Eastern hog-nosed snake Heterodon platirhinos | Colubridae | 99 | 1.2% |
| 17 | Eastern massasauga venomous Sistrurus catenatus | Viperidae | 55 | 0.6% |
| 18 | Eastern wormsnake Carphophis amoenus | Colubridae | 33 | 0.4% |
| 19 | Kirtland's snake Clonophis kirtlandii | Colubridae | 23 | 0.3% |
| 20 | Rough greensnake Opheodrys aestivus | Colubridae | 2 | 0.0% |
Also recorded in Pennsylvania, fewer than 10 times
Beyond the main list, two snake species are known from Pennsylvania by only 3 to 9 records each. Some are genuine rarities at the edge of their range; others may be strays, released pets or old misidentifications, so treat them as unconfirmed.
Related pages
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.