Outside Yuma, Arizona—not far from the Mexican border—my husband and I got lucky in finding a dispersed camping spot along the Senator Wash lake front. The reservoir water level had receded, leaving extra beach space, and I spent hours soaking in the view while walking a swath of dried lakebed. Strangely, the mud had dried into zillions of baseball size pockmarks. I wondered if some special property of the soil caused it to dry with depressions. Had some aquatic species somehow excavated indentations? Too small for people tracks…dog, coyote, bobcat, deer? Maybe, but probably too small, and anyway, that many […]