Crisscrossing Pleistocene terrace tops and overlooking the Gila River in southeastern Arizona are acres and acres of rock alignments that have perplexed archaeologists for a century. Well known but poorly understood, these features have long been considered agricultural, but exactly what was cultivated, how, and why remained a mystery. Now we know. Drawing on the talents of a team of scholars representing various disciplines, including geology, soil science, remote sensing, geographical information sciences (GISc), hydrology, botany, palynology, and archaeology, the editors of this...