The salt plains are a unique geological area. Visitors may enjoy viewing the near perfectly flat 11,000-acre barren area with the wafer thin salt crust or dig for the Famous Salt Plains selenite crystals with the hour-glass sand inclusion.

The salt was formed by repeated flooding by sea water millions of years ago. The sea water was cut off from the sea and evaporated, depositing thick layers of salt. The area was subsequently covered by erosion from mountain ranges. Below the plains, ground water travels through the salt saturated sand and comes to the surface where it evaporates, leaving the crust of salt. The concentrated saline solution combines with gypsum to promote selenite crystal growth in a portion of the salt flats.

Visitors are allowed to dig from April 1 - October 15 in the designated area. This is the only place in the world where hourglass shaped sand inclusions may be found in most crystals.

An observation tower located at the crystal area gate is open year round and provides a good view of the salt flats and western edge of the lake.

A brochure on the selenite crystals and the procedure for digging for them is available from the U.S. Fish and Wildlife Service at the Park Office.