Chetro Ketl is an Ancestral Puebloan great house and archeological site located in Chaco Culture National Historical Park, New Mexico, United States. Construction on Chetro Ketl began c. 990 and was largely complete by 1075, with significant remodeling occurring in the early and mid-1110s. Following the onset of a severe drought, most Chacoans emigrated from the canyon by 1140; by 1250 Chetro Ketl's last inhabitants had vacated the structure.