
?????
He's got two undersides? ;^) Could you clarify this one?
It's almost definitely non-poisonous (simply because there are so few poisonous ones in America), and the fact that the bands are broken towards the end of the tail (and the non-slitted eyes, and the non-triangular head, etc). If yours doesn't look like any of the pics I posted, then it probably is a juvenile (since they can look very different from the adults).
What is the shape of the nose? Is it wide, thin, or up-turned? (Hog-nosed and burrowing snakes have almost shovel-nosed shapes.)
BTW I mistyped earlier.. copperheads have yellow tails (not heads as I typed) especially when young.