Outside Great Sand Dunes National Park

The vast expanse one sees from the dunes is the San Luis Valley. Covering 8,000 square miles (and with an average altitude of 7,500 feet), the San Luis Valley is the world's largest alpine valley, sprawling on a broad, flat, dry plain between the San Juan Mountains to the west and the Sangre de Cristo range to the east, and extending south into northern New Mexico. The area is one of the state's major agricultural producers.