Cottonmouth (Water Moccasin) | Snake Road Species Guide
Cottonmouth
The cottonmouth is one of Snake Road's most iconic residents and one of the species many visitors hope to see. Despite its reputation, it is generally calm when left undisturbed and is an unforgettable sight whether encountered crossing the road, basking near water, or resting quietly beneath cover.
Quick Facts
Scientific Name: Agkistrodon piscivorus
Venomous: Yes
Average Length: 24–48 inches
Likelihood of Seeing: Common
Best Seasons: Spring & Fall
Typical Habitat: Wetlands, ditches, sloughs, and flooded forest
Identification
Cottonmouths are heavy-bodied snakes with broad, triangular heads and a distinctive dark facial mask. Adults are often dark brown to nearly black, while juveniles display bold crossbands and a bright yellow tail tip.
When threatened, they may gape their mouth, revealing the white interior that gives the species its common name.
Where to Look
Look along wetland edges, drainage ditches, flooded woods, and sunny openings near water. During migration seasons, individuals are frequently encountered crossing Snake Road as they move between overwintering habitat and nearby wetlands.
Behavior
Cottonmouths spend much of their time near water but are equally comfortable on land. They are capable swimmers and are often seen basking or lying motionless beside the road. Given space, they usually remain calm or slowly move away.
Photography Tips
A telephoto lens allows excellent photographs while giving the snake plenty of space. Early morning often provides opportunities to photograph basking individuals before daytime temperatures rise.
Interesting Facts
- Juveniles use their bright yellow tail to attract prey.
- Cottonmouths are pit vipers, closely related to copperheads and rattlesnakes.
- They are the only venomous semi-aquatic snake native to Illinois.