There are two creeks at Great Sand Dunes. Medano Creek is closest to the Visitor Center and the most popular with visitors. Depending on the conditions, visitors can surf, wade, raft, or just dip ...

For fine-grained sand the threshold wind velocity ... tabular cross-strata with a uniform dip direction parallel to the dominate wind direction as the dune migrates downwind (Photos 1 and 2).

This story appears in the November 2012 issue of National Geographic magazine. I got my first lesson in the physics of sand dunes in 1998 on an expedition into the Sahara. In order to take aerial ...

Behind many of these beaches are sand dune systems which provide homes for diverse forms of wildlife including plants and insects, some so highly specialised that without these dune habitats ...