The Black Rock Desert playa is a 400-square-mile dry lake bed, one of the flattest surfaces on earth. After winter rain it fills with a thin sheet of water and becomes a perfect mirror reflecting the sky; in summer it bakes to a hard white crust of salt and alkali, criss-crossed by cracks. You can drive out onto the playa from Gerlach — follow the BLM signs — and keep going until you can't see anything at all except the mountains on the horizon. The silence is total. The playa sits within the Black Rock Desert–High Rock Canyon Emigrant Trails National Conservation Area, a 1.2-million-acre BLM tract that preserves some of the most intact stretches of the original emigrant trail west.