Yeah, racer would be another good guess if it was long and slender...sometimes they have a pale colored belly...but as Kory mentioned...they are quite adept at finding a hole that something else created and using it as an escape route.

Mostly they borrow holes dug by other things, rodents and so forth.  Racers aren't really designed to dig their own holes.

In looking at pictures, it may be a North American Racer. What confuses me somewhat is that it went underground and knew exactly where that hole was. I didn't think snakes burrowed. It had to be fairly deep to handle a snake that long. If I can catch it out again, I will close that hole before I try to catch the snake this time.

Larry-
Pretty hard to ID on that description...if the belly was a uniform green (or probably more like yellowish) it makes me think plainbelly water snake.  Check the galleries section to see if thats what it looks like.  Does not sound venomous by your description.  If you can snap a pic and post it, we can positively ID it for you.  Good luck!