Aerial view of Sand Mountain east of Fallon, Nevada.  The dune is two miles long & 600 feet in height, known as a popular recreation locale for off highway vehicles.  The sand consists of blown Sierra Nevada granite & was part of the lake bottom of ancient Lake Lahontan, which dried up some 9,000 years ago (look on the sides of the nearby mountains especially above the camping sites for original lakeshore bathtub rings).  The dunes are constantly moving at all times, covering vehicle imprints as it sits at the east end of the Salt Wells Basin pressed against the Stillwater Range.  In the distance, though blended in, lies of the foundation remains of the Sand Springs Pony Express Station.