Located in the southeast corner of California, the Imperial Sand Dunes are the largest mass of sand dunes in the state. Formed by windblown sands of ancient Lake Cahuilla, the dune system extends for more than 40 miles in a band averaging 5 miles wide (map). Widely known as “Glamis” and a favorite location for off-highway vehicle (OHV) enthusiasts, the dunes also offer fabulous scenery, opportunities for solitude, and a home to rare plants and animals.