As in other ancient states, Inca religious reform was largely successful because it drew upon preexisting cosmological principles of the south-central Andes. In this case study involving the Cotahuasi Valley of southern Peru, I argue that during the Inca occupation of the valley, an offering tradition ended, an important ritual center was abandoned, and another ritual center was completely remodeled. At the same time, other local ritual practices continued largely unmolested. I suggest that the Inca chose to encourage these changes in Cotahuasi because the ritual landscape that the Inca encountered in the valley caused political and ideological problems that could not be overcome without changing some aspects of the valley's religion. These reforms were successful because they fit within a concept of circulating life forces that was shared by both conquerors and conquered. I suggest that this belief was a resilient long-term structure of meaning that was, and remains, part of the region's practical consciousness. AFTER THE CONQUEST OF THE INCA EMPIRE in the sixteenth century, the Spaniards attempted to strip away the indigenous religions of the Andes and replace these beliefs with Catholicism. Not only were priests sent out to convert the Andean people, but also massive efforts were made to locate and destroy the idols and priests associated with native religions (Millones 1990). While the Spanish attempts to supplant one faith with another have echoes throughout history, many states have chosen instead to co-opt local religions. In these cases, the state