Irrigation came to the arid West in a wave of optimism about the power of water to make the desert bloom. Mark Fiege�s fascinating and innovative study of irrigation in southern Idaho�s Snake River valley describes a complex interplay of human and natural systems. Using vast quantities of labor, irrigators built dams, excavated canals, laid out farms, and brought millions of acres into cultivation. But at each step, nature rebounded and compromised the intended agricultural...