Petrified dunes, furrowed by erosion into a maze of sandstone fins, are washed by waves of sunlight. This geologic wonder of eastern Utah was formed when parallel joints in the Navajo Sandstone split and weathered into narrow fins up to 500 feet high. Known as Behind The Rocks, the diminutive area rivals the grand impact of neighboring Canyonlands and Arches National Parks. Even so, of 51,100 roadless acres, less than 25% are included in the Behind The Rocks Wilderness Study Area and none have congressional protection.