Antelope Canyon is a "slot canyon", a narrow chasm in erosions in sandstone. Years of water and sand has rounded the edges to form curves and flowing shapes in the rock. Photographers love the beauty and unique shapes and lighting conditions of the canyons. Flash flooding still occurs in the canyon and may, at times, result in up to several months of closing. Since 1997 the area has been accessible only by permit as it is now a Navajo Tribal Park.