Well before dawn at 4:30 a.m., Chrysti and I met at the Humane Borders truck yard, loaded our gear for the day into the water truck, checked the tires, gas gauge and water tank levels, climbed into the truck and headed out to US 286 toward the border. We had the roads pretty much to ourselves.

Alone, but not alone. Perched atop an exposed, wind-blown ridge in the Sonoran Desert a few miles north of the Mexican border in Arizona, the graveyard resembles a sepia tone image from the 1930s—slate gray sky, brown land.