YAY for turtles! When I was back in Kentucky I had the same experience except with a baby snapper...about the same size. I wasn't going to keep HIM, though...OUCH! Then two days later was riding on an old country road there and came across a HUGE snapper, probably about 18 or 20 inches across. I didn't even go near him, but appreciated getting to see him.
Here in Denver, on my favorite bike path, there are lizards scurrying across all the time, and many of them evidently don't make it .
Happy adventures!