Many scholars and students of the West refer to "Western water law" as if it were a monolithic entity predestined to triumph over all other possible alternatives.1 The common assumption used to be that once one gets past the 100th Meridian and into semiarid and arid climates, prior appropriation is the law of the land, that it was always so since white settlement reached it, and that a transition to such as system was inevitable.2 This view must be consigned to the growing ash heap of myths about the West. The reality is that in the nineteenth century, Western water law was anything but uniform, and that in many places Eastern notions of riparian rights were not easily or suddenly abandoned. Western water law was not, as one environmental historian has noted, "the product of an immaculate conception."3 Recent Western historians have demonstrated that economic conditions and needs shaped Western water law more than aridity per se, and that appropriation itself grew out of the adaptation of the common