Temperatures here rarely climb above 12 degrees Celsius and average barely 3, a cold-winter desert where seven months of the year belong to winter. Frost can strike in any season, and during cold snaps the thermometer plunges past minus 20, with an official record of nearly minus 34 in Chubut province. Snow, strangely, is rare; the air is simply too dry to deliver it. What never lets up is the wind. Constant and ferocious, it pours off the mountains as descending cold air and scours the plains, sculpting sandstone into strange shapes and lifting so much grit that the Patagonian Desert ranks among the largest sources of dust over the entire South Atlantic Ocean. To stand out here is to lean into a gale that does not stop.

Before the Andes rose, this was a different world. Temperate forests once covered the region, and then the mountains lifted, the climate dried, and volcanoes buried the trees in ash. Mineral-rich water seeped into the fallen trunks and replaced living wood with stone, cell by cell. The result, in the heart of the desert, is one of the best-preserved petrified forests on the planet: great fossil logs lying where they fell millions of years ago, their grain and bark perfectly recorded in rock. Around them, the desert keeps its other diverse features, ephemeral rivers and glacial lakes fed by the spring melt off the Andes, brief ribbons of green and birdlife threading an otherwise austere land. The desert is, in a real sense, a forest's grave.

Life persists here, tuned precisely to the harshness. The guanaco, a wild relative of the llama, drifts across the plains in herds. The lesser rhea, a flightless bird like a small ostrich, sprints between the shrubs. There are burrowing owls that nest underground, pumas at the top of the food chain, the strange long-eared mara, and armored armadillos rooting through the gravel. The plants keep low and tough, spiny shrubs and tufted bunchgrasses that hoard what little water comes. None of it is lush, but all of it is resilient, and the desert's outskirts, where the steppe softens into grassland and forest, teem with far more life than the barren interior.

Humans have crossed this desert for thousands of years, leaving their handprints and animals on cave walls. The earliest people known by name were the Tehuelche, hunter-gatherers who moved with the seasons across the steppe. In the eighteenth and nineteenth centuries the Mapuche extended their influence north into the desert, mastering horse husbandry and controlling trade routes that linked southern Chile to Buenos Aires. Then came the Argentine state. In the 1870s the army's Conquest of the Desert campaign broke that indigenous world by force; roughly a thousand native people were killed and many thousands more taken captive, families deliberately separated to keep them from having children. It was conquest in the plainest sense, and it opened the land to the sheep-farming boom that followed. Today the desert is sparsely peopled, given over to livestock and to the oil, gas, and coal drawn from beneath it, the long human story still unfolding across an unforgiving stage.