Complex sentence: According to the anthropologist Brian Fagan, like other great houses in Chaco Canyon, Chetro Ketl was built over an extended period of time, during which the Ancestral Puebloans worked almost continuously on the structure, except when diverting their workforce to agriculture.
Split into simpler sentences: According to the anthropologist Brian Fagan, like other great houses in Chaco Canyon, Chetro Ketl was built over an extended period of time. The Ancestral Puebloans worked almost continuously on the structure, except when diverting their workforce to agriculture.