“…Previous studies of sand dunes in western North America include the immense Gran Desierto sand sea of northwestern Mexico (Lancaster et al, 1987;Lancaster, 1990), the Algodones, Kelso, Cadiz, Danby, and Parker dunes of southeastern California and western Arizona (Muhs et al, 1995(Muhs et al, , 2003Lancaster and Tchakerian 2003), the Chaco dune field of New Mexico (Wells et al, 1990), the Killpecker dunes of southwestern Wyoming (Mayer and Mahan, 2004), and the Sand Hills of Nebraska (Ahlbrandt and Fryberger, 1980). In general, these dune fields are very large (the order of 10 3-10 4 km 2 ).…”