Dean M. Chriss
White Sands and Snow, New Mexico

San Andres Mountains, Gypsum Dunefield, and Snow

(Click image to enlarge)

This image was captured on a very unusual morning. We watched the full moon in a partial lunar eclipse emerge from below a deck of high clouds before it dipped behind the San Andres Mountains. Shortly thereafter the clouds began to disintegrate allowing the sun to illuminate the foreground gypsum dunes while the distant mountains remained dark. Blowing gypsum dust softens and partially obscures the lower part of the mountains and the most distant dunes. This worst of this gypsum dust and sand storm was fortunately confined to an area closer to the mountains than my location. Several days earlier a severe winter storm left drifts of snow lingering among the dunes. Sunlight passing through high altitude gypsum dust created a dull pink tone in the sky that lasted well beyond the sunrise. These conditions combined to create an odd and otherworldly scene with lighting I have never seen before or since. Another photograph captured a little later on the same morning can be seen here.

Rain in the San Andres Mountains dissolves gypsum and washes it down to the basin floor. The water settles on the basin floor at its lowest point, called Lake Lucero. As the lake evaporates it leaves behind gypsum in crystalline form. The smaller crystals are picked up by the wind and deposited in the world's largest gypsum dunefield.