Waypoint: White Sands National Park, Tularosa Basin, New Mexico, USA
“These images and words are a reflection, simply and wholly, of my respect for our public lands and the public science and occasional art I am, and we are, able to do there. Our ability to create and think are not trivial, and wild space and healthy ecosystems nourish such things. It is here that we will find our better selves, even as the misdeeds of a few threaten much that, until recently, provides for our common good. Keep going.“
A couple times over the past two years, I have had the good fortune to wander among the gypsum dunes of White Sands National Park in south-central New Mexico. My visits dovetail with geoarchaeological research in the Tularosa Basin, where we have been looking, with the help of and collaboration with specialists and volunteers at the National Park Service and friends and colleagues at Holloman Air Force Base, at the context of human and faunal trackways along the margins of pluvial Lake Otero. The footprints are fascinating and perplexing, and the various studies implemented at Lake Otero provide comparison to our approach to somewhat similar ichnofacies on Utah’s Old River Bed Delta, a landform of the Bonneville Basin that supported an expansive wetland between 12,600 and 8,800 years ago. By bookending daytime research excursions with walks in the expansive white dunes, I had time to consider the setting, past and present, and its broader implications at a slower pace and without contention. And, sometimes, the light is so good.
The white, gypsum sand that forms the dunes is a result of a long interplay between bedrock of the mountain ranges surrounding the Tularosa Basin, basinward erosion of fine-grained minerals derived from the parent rock, catalysts of groundwater chemistry, and climate change. In the Late Pleistocene, say, between about 22 and 18 thousand years ago, Lake Otero rose and fell – by day, by season, by decade, by millennium – as runoff battled evaporation and groundwater sought equilibrium in between. These perturbations produced an evaporite soup, at times deep and dilute, and at others shallow and practically viscous. The overlap of conditions from bedrock to basin hydrology are incomparable with almost all other paleolakes in the desert west.
With the warming and drying of the last 14,000 years, the hallmark of the Holocene, a prevailing southwesterly wind scours the exposed bed of crystalline gypsum – the relict product of the Pleistocene chemistry – that bounces and rolls to become sand-sized aggregates of dune-building material; finer particles get carried away to coat the hills in desert loess or circle the globe as aerosol clay. Earth tends toward recycling.
And so, the scoured lakebed becomes the gypsum dunes of White Sands, a process still happening today. The sand subdues and reflects the color of the sky, bending the hues along wind-sculpted crests and swales. Shadows are abrupt until blue hour erases all depth, molding the reflected glow to a calm iridescence; the changes are reversed for sunrise. Although I have visited in the early morning, park hours limit sunrise opportunities to a few minutes; it is sunset that brings productive wandering. That is until park rangers begin the pre-dark patrol, broadcasting the requirement that all wanderers return to their vehicles, leaving the dunes to their nightly rearrangement.
I hope you enjoy this small gallery of images from White Sands. Active dunes are always changing; the photos you capture are yours alone, the winds bring originality. Most visitors do not venture very far into the hills of sand, so it takes little effort to get beyond the occasional messiness of a tracked-up dune. With practice or a reliable GPS, you can be confident of where you are and where your personal trailhead is. And then, you can move slowly, let the light evolve, and make the patterns your own.