El Cuartelejo, or El Quartelejo (from Spanish cuartelejo, meaning old building or barracks), is a region in eastern Colorado and western Kansas where Plains Apache cohabited with Puebloans. Subject to religious persecution, Puebloans fled the Spanish Nuevo México territory and cohabitated with the Cuartelejo villagers in the 1600s. Some people fled to the Arkansas River area of present-day Kiowa County, Colorado. Juan de Ulibarri came to the Arkansas River area of Colorado in 1706 to capture and return Pueblo Native Americans who fled Nuevo Mexico in 1680.