This is a chipmunk. He made a hole between the stones on a path - there wasn't much room!
Someone pointed him out to me, but I thought the same thing colorcarnival mentioned - he'd be too fast. I sat down and started watching him. There was a pile of nuts and raisins he would go fill up his cheeks with. Then he'd bee-line back to the hole to unload. When ever he came up his head would pop out and he'd stay like that for a few seconds. I think he was trying to squeeze his feet in place to push out. I thought it might be interesting so I set up and waited.
NO CHIPMUNKS WERE HARMED IN THE TAKING OF THIS PICTURE - haha!