The Owens lake bed lies between the Sierra Nevada to the west and the Inyo Mountains to the east. Spanning 110 square miles, the bed is vast enough that, observed from a helicopter, you cannot make out its shape. (In satellite images, its form looks something like the outline of South America, if South America were melting in the desert heat.) As you fly clockwise around the perimeter, a grid of sorts begins in the north, an ad hoc mosaic that runs the eastern length of the bed and wraps around its southern end. Many of the mosaic pieces are trapezoids, and most are gray plains of dried, cracked earth.