White Sands Nat’l Monument, NM
Just west of Alamogordo, NM is White Sands National Monument, a large dune field of gypsum sand. Gypsum is an interesting rock because it is soluble in water. Consequently, when it rains in the mountains to the west of the dune field, the gypsum there dissolves and is transported to Lake Lucero, which is just to the southwest of White Sands. When the water there evaporates, it leaves the gypsum behind to be blown into the dunes. I hiked into the dunes until I could no longer see other footprints which ended up being about a mile. When down in between the dunes, you really get the same sense of isolation and disorientation that one must get when stranded in the middle of the Sahara Desert. I spent something like two hours hiking around and climbing the large dunes. As the sun set behind the mountains and the temperature began to drop, I had a strong feeling of urgency to get back to my truck. Yeah, I wanted to grab a picture of it at sunset, but more importantly I didn’t want to be in the dunes when it got dark without a flashlight. Pictures below. I think I’ll be going back for some more at some point in the future.
Side note… After clicking on that link above, scroll north of White Sands. See that sweet black scar? That is the Carrizozo Lava Flow which erupted from a local volcano some 5,000 years ago. NASA has some more info on it.