Archaeological research conducted at four sites in the south-central Andean highlands, the consumption zone for Chivay obsidian, provide evidence for the changing use of Chivay obsidian over long time periods. This section will begin by focusing on the four sites because they important here as the sites have provided stratified evidence of obsidian consumption during the Archaic and Formative in well-dated archaeological contexts. This review of the sites will be relevant in subsequent discussions of change in obsidian use over time in the region, and for interpreting activities at the Chivay source.