Venomous Snakes in the US: Every Type and Where It Lives

The four groups of US venomous snakes

Three of the four groups are pit vipers, members of the viper family that have a heat-sensing pit between each eye and nostril, long folding fangs, and usually a broad head and vertical pupils. The fourth group, the coral snakes, belongs to the elapid family, the same family as cobras and mambas.

The species count changes as DNA studies split old species into new ones. The western rattlesnake, for example, is now often separated from the prairie rattlesnake, and the cottonmouth and copperhead were each split into two species in the 2010s.

Rattlesnakes: the biggest group

Rattlesnakes are found only in the Americas, and the US has more of them than any other kind of venomous snake. All have a segmented rattle at the tail tip, which they shake as a warning, although newborns have only a single “button” and a rattlesnake may stay silent if it relies on camouflage.

• Eastern diamondback rattlesnake (Crotalus adamanteus): the largest rattlesnake, usually 0.9–1.8 m (3–6 ft) long, in the pine flatwoods and sandhills of the Southeast. See our profile of the eastern diamondback.
• Western diamondback rattlesnake (Crotalus atrox): the common big rattlesnake of Texas, Oklahoma, New Mexico, Arizona and southeastern California, with a black-and-white banded “coon tail”.
• Timber rattlesnake (Crotalus horridus): the rattlesnake of eastern forests, from Minnesota and New Hampshire south to Texas and northern Florida, with dark chevron bands and a black tail. Read the timber rattlesnake profile.
• Prairie and western rattlesnakes (Crotalus viridis and C. oreganus): widespread on the Great Plains, in the Rockies and along the Pacific states.
• Desert specialists: the Mojave rattlesnake, sidewinder, speckled, black-tailed, tiger and rock rattlesnakes of the Southwest. Many Mojave rattlesnakes carry a potent nerve-affecting toxin.
• Pygmy rattlesnakes and massasaugas (Sistrurus): small rattlesnakes with large plates on the crown of the head. The eastern massasauga of the Great Lakes region has been listed as Threatened under the US Endangered Species Act since 2016.

Arizona has 13 kinds of rattlesnakes, more than any other state, including the rare ridge-nosed and twin-spotted rattlesnakes of its “sky island” mountains.

Copperheads

Copperheads are medium-sized pit vipers, usually 50–95 cm (20–37 in) long, with tan to coppery bodies crossed by darker hourglass-shaped bands that are narrow on the back and wide on the sides. Young copperheads have a bright yellow or greenish tail tip that they wiggle to lure frogs and lizards.

The eastern copperhead (Agkistrodon contortrix) lives from Massachusetts and Connecticut south to the Florida Panhandle and west to Texas, Kansas and Nebraska. The broad-banded copperhead (A. laticinctus), treated as a separate species since 2015, lives from Kansas through Oklahoma into central Texas.

Copperheads rely on camouflage and often freeze instead of fleeing, so people step on or near them in leaf litter, woodpiles and gardens. That makes them a leading cause of venomous bites in many eastern states, but their bites are rarely life-threatening for healthy adults. Learn more in our copperhead profile.

Cottonmouths (water moccasins)

Cottonmouths are heavy-bodied, semi-aquatic pit vipers, usually 0.6–1.2 m (2–4 ft) long, that live in swamps, marshes, ponds, ditches and slow rivers. Young snakes are boldly banded with a yellow tail tip; adults darken until some look almost black. When threatened, a cottonmouth may coil and gape to show the white lining of its mouth.

The northern cottonmouth (Agkistrodon piscivorus) ranges from southeastern Virginia to the Gulf Coast and west to eastern Texas and Oklahoma, and up the Mississippi Valley to southern Illinois. The Florida cottonmouth (A. conanti) lives in peninsular Florida and southern Georgia. Field studies show cottonmouths usually try to escape or warn rather than bite. See our cottonmouth profile.

Coral snakes

The US has three coral snakes, all slender, secretive snakes ringed in red, yellow (or white) and black:

• Eastern coral snake (Micrurus fulvius): the coastal plain from North Carolina to Florida and west to Louisiana. Read the eastern coral snake profile.
• Texas coral snake (Micrurus tener): Texas, Louisiana and Arkansas, south into Mexico.
• Sonoran coral snake (Micruroides euryxanthus): Arizona and southwestern New Mexico, only 28–61 cm (11–24 in) long.

Coral snake venom acts mainly on the nervous system, but these snakes spend most of their time under leaf litter and soil and bite only when handled. Fewer than 1% of US venomous snakebites are from coral snakes.

Where venomous snakes live, region by region

• Southeast: all four groups, including the eastern diamondback, timber (canebrake) and pygmy rattlesnakes, copperheads, cottonmouths and the eastern coral snake.
• Northeast and Midwest: mainly timber rattlesnakes and copperheads, plus the eastern massasauga around the Great Lakes. Many northern populations are small and protected.
• Great Plains: prairie rattlesnakes, western massasaugas and, in the south, broad-banded copperheads.
• Texas: rattlesnakes, both copperheads, the cottonmouth and the Texas coral snake.
• Desert Southwest: the most rattlesnake species, plus the Sonoran coral snake.
• Pacific states and the Rockies: rattlesnakes only. California, Oregon and Washington have no native copperheads, cottonmouths or coral snakes.

Alaska and Hawaii have no native venomous land snakes. Maine and Rhode Island are also generally considered free of them today, because the timber rattlesnake has disappeared from both states. The only exception at sea is the yellow-bellied sea snake (Hydrophis platurus), a highly venomous open-ocean species that sometimes reaches Hawaii and has washed up on beaches in Southern California.

How common are snakebites?

The CDC estimates that 7,000 to 8,000 people are bitten by venomous snakes in the US each year and that about five die. Rattlesnakes cause most serious bites, and the two diamondbacks account for the large majority of deaths. Many bites happen when people try to catch, move, kill or handle a snake, and others when someone steps on or reaches near a hidden one.

Deaths are rare because emergency care and antivenom are widely available, but every venomous snakebite is a medical emergency. Children and older people are at greatest risk.

Identification myths

• “Venomous snakes always have triangular heads.” Coral snakes have narrow heads, and harmless snakes such as water snakes and hognose snakes flatten their heads when alarmed.
• “You can check the pupils.” Pit vipers have vertical pupils and coral snakes have round ones, and you would have to be dangerously close to see either.
• “Rattlesnakes always rattle first.” Many stay silent and rely on camouflage, and a newborn cannot rattle at all.
• “Red touches yellow, kills a fellow.” The rhyme fits the three US coral snakes but not coral snakes elsewhere, and odd color patterns occur. Our article does the coral snake rhyme work? explains its limits.
• “Snakes chase people.” Snakes do not hunt people. A snake moving toward you is usually heading for cover.

Staying safe around venomous snakes

• Keep your distance. Give any snake plenty of room and never try to touch, catch, move or kill it.
• Watch where you step and reach, especially in tall grass, leaf litter, rock piles and woodpiles, and use a flashlight on paths at night.
• Wear boots and long pants when hiking in snake country.
• If someone is bitten, call 911 and seek emergency medical help immediately.