Before construction of the Interpretive Center began in 1988, archaeologists spent two years excavating this area and found evidence of residential use, including more than 80 houses and storage buildings and several hundred storage and refuse pits. Cahokians reused this area many times between AD 1050 and 1275. At Cahokia Mounds, four distinct time phases are identified based on changes in structure size and orientation, as well as the number of structures and settlement patterns: Lohmann, Early Stirling, Late Stirling, and Moorehead. The patterns of these structures and features are painted on this patio directly above the locations where archaeologists found them.