The National Park showcases the continuous work of wind, water, and time. Sand captured by the unique topography of the massive and nearly vertical Sangre de Cristo Mountains creates the tallest inland dunes on the continent. Medano Creek flows seasonally at the base of the dunes, providing a place where visitors enjoy sand, water, and sun in a spectacular mountain setting.
The highest dunes in North America appeared as a "sea of sand" to Zebulon Pike in 1807. Prevailing southwesterly winds sweep up ancient grains of sand and then deposit them grain upon grain at the base of the Sangre de Cristo Mountains. Two major attractions are "High Dune", rising 650 feet above the valley floor and Medano Creek, a lazy seasonal stream that pulses with waves during periods of high water. This mosaic of sand, water, and mountains forms one of Colorado's most distintive landscapes.