Footprints in the sand, Eureka Dunes.  The Eureka Valley Sand Dunes are California&#39;s tallest sand dunes, and one of the tallest in the United States.  Rising 680&#39; above the floor of the Eureka Valley, the Eureka sand dunes are home to several endangered species, as well as &#34;singing sand&#34; that makes strange sounds when it shifts.  Located in the remote northern portion of Death Valley National Park, the Eureka Dunes see very few visitors