This is called the Rim Trail because it follows the White River Valley upriver from the dam...400ft. above the valley floor. In many places along the trail you find these rail fences and signs to keep you from the edge. Much of the rim is undercut from erosion either from the river itself or from the soft earth giving in to gravity. Three years ago a woman's dog didn't heed the sign and got stuck on a wide ledge just below the rim's edge. The woman crossed the boundries of safety to save her dog....the dog survived, she didn't. Unfortunately many people in these mountains don't heed the warnings posted for their safety. It seems every year we lose a few careless hikers...some just for the thrill. If the sign says danger, believe it!!!