Saw this little guy booking across the path by the Spillway on Monday afternoon.

He moved so fast I couldn't put a quarter next to him to give you a sense of scale, but his shell was smooth, domed and a bit beat-up and muddy. He was about 4 inches long.

From all I can gather, it is a Musk Turtle. Other input most appreciated.

More on Musk Turtles here.