Agkistrodon contortrix


While the copperhead (Agkistrodon contortrix) is neither endangered nor threatened in the state of Pennsylvania, it is identified as a maintenance concern. Continued population stability is important as Pennsylvania may function as a stronghold for this species in the northeastern United States.


The copperhead is the most common venomous snake in much of its range which extends from southern Massachusetts south to Georgia and west to Texas and Illinois. Five subspecies have been identified with one – the northern copperhead (A. contortrix mokasen) – occurring in Pennsylvania. Favored habitat for the northern copperhead includes rocky, wooded hillsides. It is not uncommon to find copperheads and timber rattlesnakes lying side by side.

Copperhead (background) and timber rattlesnake (foreground)

Northern copperheads are medium-sized, heavy-bodied snakes with average adult lengths ranging from 24-36 inches. Rodents are the favored food but amphibians, small reptiles, and even insects are consumed, especially by younger individuals. Copperheads are viviparous (give birth to live young) with litters ranging from 4 to 9 snakes. The species is known to be gregarious during winter hibernation and may den with other species of snakes.


Aqua-Terra has conducted telemetry studies of two Pennsylvania copperheads. Information pertaining to habitat use, movements and hibernacula were obtained. Many thanks are extended to Dr. Howard Reinert and Scott Fiegel for completing the transmitter surgeries.

Jay Drasher and a 37-inch Pennsylvania copperhead (September 2004)