Results of survey and test excavations at the Chivay obsidian source in highland Peru found evidenceof use of the source area throughout much of the prehispanic past. An examination of a quarry pitand workshop suggest that quarrying and workshop production intensified at the end of thePreceramic period in the region. The high elevation Chivay source (71.53558 E, 15.64238 S) lies at4950 masl and was the geological origin for prehispanic obsidian artifacts from throughout much ofsouthern Peru and Bolivia. Radiocarbon dates on charcoal recovered from the lower levels of a testunit placed in a mound of obsidian debris at the workshop, together with an obsidian hydrationsequence from test units at both the workshop and the quarry pit, point to an amplification ofquarrying and workshop production during the Terminal Archaic, or the third and secondmillennium BC. Regional exchange networks and trade in exotic goods are extensive during laterperiods in Andean prehistory but these data suggest that obsidian as an early target of procurementover distance was prepared in a dense production deposit that reflects changes over time.