Results of survey and test excavations at the Chivay obsidian source in highland Peru found evidence of use of the source area throughout much of the prehispanic past. An examination of a quarry pit and workshop suggest that quarrying and workshop production intensified at the end of the Preceramic period in the region. The high elevation Chivay source (71.5355° W, 15.6423° S) lies at 4950 masl and was the geological origin for prehispanic obsidian artifacts from throughout much of southern Peru and Bolivia. Radiocarbon dates on charcoal recovered from the lower levels of a test unit placed in a mound of obsidian debris at the workshop, together with an obsidian hydration sequence from test units at both the workshop and the quarry pit, point to an amplification of quarrying and workshop production during the Terminal Archaic, or the third and second millennium bc. Regional exchange networks and trade in exotic goods are extensive during later periods in Andean prehistory but these data suggest that obsidian as an early target of procurement over distance was prepared in a dense production deposit that reflects changes over time.