No Deposit, No Return

Early one May morning, I escaped Tucson’s unrelenting grid and drove south through Pima County on Arizona’s state Route 83, into the heart of the Madrean Sky Islands, an almost mythical landscape of shadowy, isolated peaks where several biological zones overlap. The blue-gray Whetstone Mountains marked the distant eastern horizon, the Patagonias loomed to the south, and to the immediate west rose the camelback ridgeline of the Santa Ritas. There, oaks and junipers stippled upper elevations, and rolling swells of grass blanketed low slopes. A haven for wildlife and a balm for those seeking respite in nature, this region contains some of the rarest intact ecosystems and the highest-quality streams among the deserts of the Southwest, providing habitat for ocelots, jaguars, and a dozen other endangered species.

I parked just off a rutted dirt road in the Coronado National Forest and walked several miles through sagebrush, mesquite, and brightly colored wildflowers. I was looking for old mining claim stakes and signs of big cats but contented myself with vultures, mule deer, and rabbits. Long before Spanish and American colonization, Native peoples prospected these mountains, leaving small scars on the hillsides. More than a century of grazing has helped woody shrubs displace grasslands, a process that climate change is exacerbating.

But worse may soon come. In 2017, the Forest Service, mandated to promote both production and recreation on public lands, approved a plan for the Rosemont Copper Company, a subsidiary of Canada-based Hudbay Minerals, to gouge some 660 million tons of rich ore out of this ground. To get at the precious metal, the company plans to excavate a conical pit roughly a mile wide and some 2,900 feet deep—sufficient to bury the Burj Khalifa, the world’s tallest structure. As it burrows through the water table, Rosemont will spit out 1.2 billion tons of waste rock and another 700 million tons of tailings, the finely ground material left after most metals and minerals have been extracted from ore, to be dumped and piled in massive heaps over several thousands of acres of adjacent Forest Service land.

The forest, the grasslands, and the washes that drain them will be no more. Mountain views will be obliterated, along with 18 miles of streams. When mining operations conclude approximately 20 to 25 years after they start, a deep lake will form inside that ore pit. Not only will this perpetually evaporating sink concentrate heavy metals and likely become toxic, it will also permanently reverse groundwater flows away from seeps, springs, and riparian areas for miles around.

I reached a spot within the mine’s planned footprint and sat. The wind shushed, and butterflies flitted. In 100 years, much of what was before me would be underwater, and the golden corrugation of land to the east would be buried under mounds of debris. Rosemont calls the shapes it would create “landforms”—a word that usually describes natural features. The company’s computer renderings of the site,