Eastern Copperhead

Agkistrodon contortrix


Image of an osage copperhead
The eastern copperhead is the most common venomous snake in Missouri. Its color varies from grayish brown to pinkish tan, with distinctive hourglass-shaped crossbands.

Viperidae (venomous snakes) in the order Squamata (lizards and snakes)


Color varies from grayish-brown to pinkish-tan, with hourglass-shaped crossbands of dark gray, brown, or reddish-brown. The head may have some pink or orange color, hence the name “copperhead.” The tail may be yellow or greenish yellow, especially in young specimens, and the belly usually is a dusky mixture of gray, tan, and black. Copperheads are pit vipers, with an opening on each side of the head and (in daylight) eyes with catlike, vertical pupils (all our nonvenomous snakes have round pupils).

Copperhead venom is considered mild compared to that of other venomous snakes, but medical treatment should still be sought if a person is bitten.

Missouri has two subspecies of eastern copperhead: The Osage copperhead (Agkistrodon contortrix phaeogaster), found in the northern two-thirds of the state, and the southern copperhead (Agkistrodon contortrix contortrix) in the southern third.


Length: 24 to 36 inches (2–3 feet).


Video of an Osage copperhead in the wild.

Eastern Copperhead on the KATY Trail

A snake is sprawled across a gravel trail. Its coppery hourglass bands are clearly visible.
A copperhead suns itself on the KATY Trail in St. Charles, MO

Eastern Copperhead Swimming

a copper-colored snake with a dark hourglass pattern on its back swims in a river
Copperhead swimming in the Meramec River near Leasburg
Habitat and conservation

Copperheads live on rocky hillsides and along forest edges. They also spend time among trees and brush along prairie streams and are often found near abandoned farm buildings. They often rely on their camouflage pattern when resting in dead leaves and will usually remain motionless when encountered. They’re not aggressive, and they seldom strike unless provoked. Look where you step, wear protective footwear, and don’t stick your hands under rocks or logs. If you see a copperhead, let it be.


Copperheads eat mice, lizards, frogs, small birds, insects (especially cicadas), and sometimes small snakes. Young copperheads use their yellow tail as a lure to attract small frogs or lizards.

Eastern Copperhead Distribution Map
Distribution in Missouri

Statewide, except for the extreme northern border with Iowa. The Osage copperhead subspecies occurs in the northern two-thirds of the state. It is replaced by the southern copperhead subspecies in the southern third.


This is our most common venomous snake, and it is common in suitable habitats. All snakes native to our state are protected by law. It is against the law to kill them, except when a venomous snake is in such close association with people that it might result in someone being bitten.

Life cycle

Copperheads are normally active from April through November. Courtship and mating occur in the spring. Young are born in August through early October. Females produce young every other year. There are 1–14 young in a litter. The optimal temperature for copperheads is 80F. They bask on warm sunny days, especially in the morning. In the hottest months, they become nocturnal. In autumn, they gather together to overwinter at south-facing rocky ledges.

Human connections

Copperheads help control populations of mice, which often have negative economic impacts on agriculture. The fear and curiosity that pit vipers inspire in humans often provoke us to learn more about reptiles, ecology, and other aspects of natural history.

Ecosystem connections

Copperheads hunt for a variety of small animals, but mice make up most of their prey, so copperheads play an important role in limiting their populations. Other species, in turn, consume copperheads. Kingsnakes, for example, are immune to their venom and will eat them if they get the chance.