A hill or ridge of loose sand shaped by the winds. Sand Dunes are found on the windward side of the Sangre de Cristo Mountains in the San Luis Valley. The dunes are recognized as a national monument. (Great Sand Dunes National Monument).
Mounds of sand created by wind picking up sand and depositing it when an obstacle is encountered.
Mounds of sand, usually on the beach facing the surf. Containing specific types of vegetation. The faster the winds, the bigger the dunes.