White Sands is not just a missile range but an amazing National Monument with some of the most unique sand dunes you’ll ever see.
The 275 square miles (712 sq.kms. or 176,000 acres) of dunes at White Sands National Monument are the largest gypsum dunes in the world. They are are not made of sand (silicon dioxide, Si02) but gypsum (hydrous calcium sulphate CaSO4•2H20). Gypsum is the main ingredient in drywall (gypsum or plaster board) which is used to finish walls and ceilings. Unlike sand, which tends to be brownish in colour (even the so called ‘white sand beaches’ are actually light brown), gypsum sand is pure white.
Gypsum is rarely found in a solid form as sand because it is water soluble and would normally wash away to the sea, but White Sands National Monument is located in the Tularosa Basin, a large depression in the New Mexico desert that 250-million years ago was at the bottom of shallow sea, and today is ringed with mountains, so no water courses drain it. Crystals of gypsum (called selenite) up to 3 feet long form in beds at Alkali Flats along the shore of Lake Lucero. The natural elements break these crystals down into small particles that migrate with the wind to form amazing dunes of soft white sand that feel look and feel like talcum powder.
Since gypsum is water soluble, the sand that composes the dunes can dissolve and cement together forming a hard layer similar to drywall. The road through the monument is made of gypsum and it’s like driving on a giant sheet of drywall.
A great thing to do at White Sands is dune sledding. Bring your own disc or purchase one at the visitor’s center, then head to the largest dunes.
Hiking up the sand dunes is a great workout, like extreme hiking. With every step up you slide down one-half step. The soft footing requires all sorts of supporting muscles.
After a couple of hours of hiking up and sliding down, I was exhausted
Diane seemed fine. She couldn’t stop smiling and laughing, like a kid playing in the snow.
At the close of the day, we still had enough energy to go on a sunset walk led by a ranger. It was an informative and relaxing ending to a terrific day.