Sand dunes and mountains, Panamint Valley, California, looking north.? The dunefield, at the north end of the valley, concentrates sand from the full 100 mile length, here being carried in a counter-clockwise, east to west. ?The dune edges are in continuous motion and state of miniature avalanche, one of the examples of fractal geometry present, along with the wave/ripple pattern in the dune surfaces. ?The lee, downwind surfaces provide just enough shelter for seeds, (and very hardy vegetation)