How far is ‘too far’? - Mesquite Flat Dunes, Death Valley National Park
In fact the person in the photograph wasn't that far, its perspective of 10-22mm lens.
Many photographers were in search for dunes with undisturbed edges and have to walk far far away to reach them.
These dunes are located off of Highway 190 near the Stovepipe Wells area of Death Valley National Park.