Judging by the brown color on the back of the one above, it is young. It never came out from the Dog Fennel plant any farther, but I'd guess this one was about 18" in length. Adults grow to about 3ft in length.
suspot, you have no idea how true your statement is. My yard is filled with all kinds of plants and animals. I should break out the old video camera with the night vision, and see what I can find during the night. I see raccoon tracks almost daily, occasionally deer tracks, saw a fox in the driveway a while back. Fiddler crabs, other snakes, skinks, plenty of birds, cats, other dogs, yellow jacket nest, ants, Ant Lions, Anoles, butterflies, beetles, Hooded Mergansers (ducks), Hawks, saw a Sora (bird) the other day, I could go on. Did I mention ants? There are ants everywhere -- fun to watch build their mounds. Wish I had a time lapse camera of the close up of that. I'm have enough that I am starting a blog about it.