I got an education on the ID of this Juvenile Cottonmouth by several people. The color I think is what made me think that this was a Copperhead. Thanks to everyone that took the time to explain the difference between the two on Facebook and here on my blog.
I spotted this Cottonmouth crossing the road at the Sequoyah National Wildlife Refuge in Oklahoma. Instead of slithering away it froze which allowed me to take a few photos.
Common names include variants on water moccasin, swamp moccasin or black moccasin; also cottonmouth, gapper, or simply viper. Many of the common names refer to the threat display, where this species will often stand its ground and gape at an intruder, exposing the white lining of its mouth.