Sunset at Great Sand Dunes National Park and Preserve, CO reveals the natural order of things. At the bottom of the image is the verdant San Luis Valley. Hidden below that, extending 10,000 feet deep is the aquifer that brings life to the surrounding area. Behind the valley floor are the beautiful sand formations of Great Sand Dunes National Park. The most prominent one in the image is Star Dune, the tallest dune in North America. Further back is a slope that leads up to the nearest...