“Between {{small-caps|a.d.}} 1130 and 1180 a period of severe drought struck the Colorado Plateaus; this is the same time during which the {{w|Roads of Chaco|Chacoan system}} appears to have disintegrated. Using the year {{small-caps|a.d.}} 1150 as the beginning of the {{w|Pueblo III period}} recognizes the potentially widespread importance of a real event in {{w|Ancestral Puebloans|Anasazi}} history; the end of building and probably, for 100 years, of occupation in {{w|Chaco Canyon}}. This is no small event given Chaco's role as a major center of activity, population, and exchange.”