Other
Sc Reptiles & Amphibians: Eastern & Florida Cottonmouth
South Carolina Reptiles & Amphibians profiles the eastern cottonmouth. A great site for photos-- both the eastern and Florida cottonmouth are pictured.
University of Florida
Cottonmouth Identification Key
An identification key for the Florida and eastern cottonmouth water moccasins.
Other
Chicago Herpetological Society: Cottonmouth
Great color photographs link to a regional map and additional information on the Cottonmouth snake.