New York has 3 venomous snakes named by official sources: Northern Copperhead, Eastern Massasauga and Timber Rattlesnake. Each one is labelled venomous by NYSDEC and NYSDEC, reprinted from New York State Conservationist.
The 3 venomous snakes of New York
Recognize them from a distance; a photo cannot confirm that a snake is safe. Identifying animals safely.
Usually 18 to 30 inches long (New York DEC: 18 to 40 inches, average 27.5). The western massasauga in Arizona reaches only about 22 inches.
How to recognize it
A segmented rattle (a single button in newborns) and vertical, catlike pupils. In Michigan it is the only snake with both.
Nine large plates on top of the head (the timber rattlesnake has many small scales there)
A heat-sensing pit on each side of the head between the eye and nostril; the head is flat and much wider than the neck
Where in New York
There are only two known populations remaining in New York, both of which occur in boggy, forested wetlands NYSDEC
Conservation
New York Endangered; Federal Threatened
What the sources say
Venom: “The massasauga rattlesnake is the smallest of the three venomous snakes found in New York State, the other two being the timber rattlesnake (Crotalus horridus) and the copperhead (Agkistrodon contortrix).” (NYSDEC)
“The venom, which is used primarily to immobilize prey, can be fatal to humans if the bite is untreated …” NYSDEC
Size
Most adults 36 to 60 inches (3 to 5 feet); record 74.5 inches.
How to recognize it
Black tail ending in a rattle
Heat-sensing pit between nostril and eye
Large, thick head distinct from the neck; cat-like vertical pupil
Where in New York
They are now found in smaller numbers throughout the state with isolated populations in southeastern New York, the Southern Tier, and in the edges of the eastern … NYSDEC
Conservation
New York Threatened
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155 records by month.What the sources say
Venom: “…the timber rattlesnake is the largest venomous snake in New York.” (NYSDEC)
Range: They are now found in smaller numbers throughout the state with isolated populations in southeastern New York, the Southern Tier, and in the edges of the eastern Catskills and Adirond
Habitat: Timber rattlesnakes are generally found in deciduous hardwood forests in rugged terrain. (NYSDEC Division of Fish and Wildlife)
For 8 other snakes on New York's list, no official source we use states whether it is venomous: Common Ribbonsnake, Common Watersnake, Eastern Hog-nosed Snake, Eastern Ratsnake, Eastern Wormsnake, Northern Black Racer, Queensnake and Short-headed Gartersnake. That does not make them harmless. Leave every snake alone.
Florida Museum (midland watersnake): the watersnake's crossbands are darker, narrower and much more numerous than a copperhead's and turn into blotches halfway down the body. Watersnakes have round pupils and dark vertical lines near the mouth; copperheads have no such lines.
Copperheads have bold hourglass-shaped bands, and young copperheads under about 12 inches have bright yellow tail tips. Brown snakes have small spots, not hourglass bands.
Brown Snake (Dekay's Brownsnake) or Red-bellied Snake?
Missouri: red-bellied snakes are sometimes mistaken for young copperheads. Copperheads are stout-bodied with hourglass-shaped markings on the back, vertical pupils, a sensory pit between each nostril and eye and, sometimes, especially in young copperheads, a yellow tail tip.
“Other kinds that occur all across New York in appropriate habitat are the green, redbelly, brown, and ringneck snakes; all four of these are small, slender, and completely benign species”
“They are completely harmless to people.”
“The milk snake is harmless.”
“The copperhead is mainly found along the lower Hudson Valley south of Kingston and scattered through the Catskills.”
“…this latter species is a large venomous snake that does not occur within our state borders.”
Eastern Massasauga. NYSDEC. archived copy, captured July 15, 2026; checked November 3, 2026.Quoted passages (1)
“The massasauga rattlesnake is the smallest of the three venomous snakes found in New York State, the other two being the timber rattlesnake (Crotalus horridus) and the copperhead (Agkistrodon contortrix).”
Timber Rattlesnake. NYSDEC. archived copy, captured October 15, 2026; checked November 3, 2026.Quoted passages (5)
“…the timber rattlesnake is the largest venomous snake in New York.”
“The venom, which is used primarily to immobilize prey, can be fatal to humans if the bite is untreated. However, in New York there have been no records of human deaths attributed to rattlesnakes in the wild during the last several decades.”
“Do not panic! Keep a safe distance of 6ft or more away. Let them move along on their own. Do not kill or collect the individual.”
“Timber rattlesnake have an active season that runs from late April until mid-October. In Northern New York, emergence is often delayed until mid-May.”
“To report sighting, or ask questions, contact your Regional Wildlife Office”
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