There are several areas set aside within the recreation area for exploration by foot, safely fenced away from the OHV areas. The Jericho and White Sands (shown here) areas are accessible by road within the park. A much larger (9000 acres) OHV free area, named the Rockwell Outstanding Natural Area, is located at the west edge of the park and accessed by non-paved roads.

The dunes were formed when wind blown sand particles were captured by the low lying mountains of the area, including Sand mountain. The sand originated in a very old very large river delta formed by the Sevier river during the Pleistocene time (2 million to 10 thousand years ago). The Sevier carried its debris from the eroding slopes of glacier capped mountains in central Utah. Several forms of dunes may be observed including low parabolic, barchan, transverse barchan and climbing dunes.