Perhaps the final frontier for exploration in the American Southwest, the Colorado River and its tributaries offer some of the deepest and most remote slot canyons to be found anywhere in the world. These narrow chasms and passages, formed through eons of rain and flooding, are often hundreds of feet deep yet only a few feet wide. With names like Elve’s Chasm, Silver Grotto and Vasey’s Paradise the known wonders of the inner gorge of Grand Canyon showcase mystical pockets of life contrasted by the surrounding arid desert. Yet because many slot canyons are too thin to find their way onto a USGS topographical map they remain unexplored and unseen by the human eye.