Sand waves...  (There are also waves within the waves.  Dunes are fractal in nature- the ripples on the surface mirror the overall shape of the dune fields.  The snow adds yet another dimension.)

Deer tracks traverse this steep wall of sand so precisely.  Its neat how the dune drops to the stream so steeply and then just ends.  There are no little 'foothills' or piles around, just an edge a few inches above the shallow waterline.  This stream is only a few inches deep at its deepest point here - just some braided rivulets thru the sandy mud.