The Tortoise (or turtle?)

I have a lot of wildlife of all sorts here. Now and again I see a snake, usually a rattler, I see more lizards than can be counted and the occasional toad comes hopping by as well. However, one evening last week I walked the dogs down to the gate to check on the status of the driveway after the recent heavy rains and found this fellow:

tortoise

The dogs and I skirted around so as to not bother him and I was not able to do a close inspection. I have never seen a turtle or a tortoise on my property and this did not look – to me at least – like a box turtle, the most common in my area, so I am wondering if he was a tortoise. I have not seen him since so I hope he found his way home again.