On the north side of the valley, you’ll pass by groves of some of the largest aspen trees you’ll ever see. At this point, you’ll also begin to encounter some of the rock formations that give this hike its name. As you might imagine, different lighting produces different effects. This is one of those hikes you’ll want to do more than once, at different times of the day. In early October the Aspen leaves all change from green to gold at the same time. We were a weekend too late for good pictures; don't you be.