Decline of Chaco Civilization

Timeline

1. c. 1130–1180Chaco Canyon agricultural zone · New MexicoTree-ring climate records show a great drought lasting about fifty years beginning around 1130 in the American Southwest; maize cultivation and water sources deteriorated, and the agricultural base supporting large settlements was undermined. Great House construction ceased around 1130.
2. c. 1050–1130Chaco Canyon Great Houses · New MexicoGreat Houses such as Pueblo Bonito underwent massive expansion around 1050–1110, with timber hauled in from mountains dozens of kilometers away. Construction stopped around 1130, and the ceremonial building system symbolizing regional integration could no longer be sustained.
3. c. 1130–1150Chaco cultural sphere · Four CornersFrom the 1140s the Chaco system disintegrated; populations migrated toward areas with more reliable water such as Mesa Verde and the Rio Grande Valley, and the buildings of the central canyon were sealed and abandoned.