Anything is possible in Alaska’s wildlands, even deserts. Kobuk Valley National Park is home to three sets of sand dunes, remnants of retreating glaciers from the Pleistocene epoch. But, as with everything else in Alaska, don’t expect the ordinary sandy scenery: Kobuk Valley’s dunes are now covered with the short trees, shrubs, and lichen typical of the tundra. An aerial tour of the Delaware-size park will display the beautiful winding Kobuk River, endless speckles of lakes, and perhaps also a wandering herd of caribou.