No way in hades I would EVER ride those mules on the trail!!!! The 2 summers I worked at the North Rim I saw several mule trains going down or up and they scared me silly getting so close to the edge, and I wasn't even on them. I know they are sure-footed and stuff but still... that was 30+ years ago when I didn't have such an intense fear of heights as I apparently do now, and it scared me silly then. I can't even imagine seeing them now...