Species ID? Found in central IA.

Encountered this guy in Boone IA today - swimming in the creek.

http://img.photobucket.com/albums/v1.../gIMG_8655.jpg

http://img.photobucket.com/albums/v1.../gIMG_8653.jpg

If it helps, he was practically floating in the water - I've seen a few other water snakes out at Ledges but they've always been mostly submerged with only their head showing - this guy was gliding along, almost on top of the water. Heavier bodied than what I usually see out there too.

Looks like a northern water snake.

Yep, I'd also go with Northern water snake (Nerodia sipedon)