Driving south toward Alamogordo, New Mexico, can be a pleasant trip in itself, but most people heading that way are planning to visit the White Sands National Monument. This wonder of nature in the southwestern US state can be reached by Highway 70. Driving 24 kilometers southwest of Alamogordo brings you to the visitor center, where you can get your first feel for what there is to see and how to plan your visit. It is recommended that you watch the 17-minute introductory movie and pick up the plastic sleds you’ll likely use later, especially if you have any kids in your group. After that, you’re all set to start the 26-km. loop of a car ride around the wondrous white dunes of sand.These “sands” are not really the traditional sand we all know, which is made up of quartz particles. Here, the sand is pure gypsum (hydrous calcium sulfate), which gives it its white appearance. The process of the dunes’ formation starts in an ephemeral lake in the western part of the monument. This rich mineral lake dries up and leaves mineral deposits on its surface, forming gypsum crystals that break into small fragments and make their way east on the strong winds. Eventually the glistening white dunes take shape.In fact, though, the White Sands’ story began 250 million years ago, when layers of gypsum were deposited in the Tularosa valley. Seventy million years ago, the whole region was raised up in the geological process responsible for the elevation of the rocky mountains in the north. Ten million years ago, the last stage created the basin that has locked the gypsum in place ever since, a closed system affected by the water and the wind.As the area is part of the Chihuahuan Desert, the air gets very hot. At an elevation of more than a kilometer above sea level, thunderstorms are typical during the summer months, usually in the afternoon. Don’t let this deter you from your visit, though. Once the rain subsides, you can continue to enjoy the white sands.The experience of rain in the desert in the middle of the summer is wonderful in itself.The sands actually cover an area of about 440 square kilometers, only 180 sq.km. of which are included in the national monument. In this natural habitat, one can see the evolutionary results of animals and plants that have adapted to the harsh conditions. One of their characteristics is a light-to-white color, evident in the bleached earless lizard, the Apache pocket mouse and the Cowles prairie lizard, among others.