water snake.....

the darker colors make me lean towards moccasin.

By the pattern and shape of the body as well as the size of the head, I'd probably have to say it is either a northern or banded water snake. I own tons of them and some of my bigger ones look exactly like this guy here. They are extremely aggressive when handled but are not venomous and will usually retreat underneath water or damp debris when encountered. I actually found my very first water snake, which happened to be a gravid female, crawling from a tree next to a river much like this one. Head shape alone cannot be reliable for telling venomous from none venomous, the best way to tell is by the eyes, none venomous have rounded pupils. while venomous have slanted pupils. Another good way is that all vipers like moccasins have more pertruding heat sensors above their top "lip" and above their eyes and have far more segments of glands there than a non venomous one.

"More pertruding" and "more venom segments." This must be resurrect the snake post and espouce disinformation day.