Nope, not poisonous. Just a common variety water snake. Also note the glassy colored eyes. That's an indication it is sheeding it's skin. When this happens the dead skin covering their eyes looks milky white and at these times snakes are more aggressive. Only assuming it causes them not to see as well so they strike first, ask questions later. The diamond shaped head in the picture is just a defense. He's mimicing a poisonous snake. Most colubrids you encounter will do this, allong with vibrating their tails in the dirt, leaves and grass to sound like rattles.

looks like a bull snake to me.

If it crawls on it's belly, it should die.

I think you should invest in a really good zoom lens if you are going to continue with your newly found obsession.

Nice pics

I've never seen a snake I'm scared of.It's the one I don't see that worry me.Kinda like that in life too..

Most cotton mouths will have a fat body and short blunt tail end. Common snakes are the same diameter all the way down.

Cottonmouths also have a dark diagonal stripe along the side of their head.

Cool pics! Definitely a nonvenemous snake. The triangular head is not an indication of a venemous snake. Many nonvenemous snakes flatten their heads out and imitate venemous varieties. Lots of poisonous ones, including our own coral snake, have round heads. BK, C.Guts, and BK have all stated good points. It looks like it might be a diamondback watersnake--way more common than a cottonmouth. The ultimate proof that it isn't a cottonmouth is the gaping mouth in the strike shot--if it is pink, it's definitely not a cottonmouth (thus the name). Great job!

Cottonmouth, or no??

It's not poisonous. It's not a bull snake. It's probably not a diamondback water snake, they have an unusual reflexive strike if you touch them, which I don't. It's a ... Texas Rat Snake, probably. It will bite you but you won't die. It's quick, too. Next time you see him snatch him up real quick and get a picture of the bottom scales, that's a good way to ID him. Or not. They're a little aggressive.

Natural selection has made people like yourself very rare

Kelly,
If it is, it would be "brown cotton" no matter how you look at it.

Kelly,

I think he's asking for a re-fill?

good pictures. non-poisonous water snake. his eyes are clouded over prepatory to shedding his skin. was he dark all over? look him up in a field guide next time you're in the bookstore.