Mesa Verde, in south- western Colorado, was one of the most developed communities of the Ancestral Puebloans (also referred to as the Anasazi).
Although people lived on or around Mesa Verde from at least 600 CE, the "cliff dwellings" that draw visitors today represent only about the last 75 to 100 years of occupation. They date from a period when Anasazi throughout the southwest began move up from the valley floors to defensive positions perched high in the cliffs or on the tops of buttes and mesas.
Mesa Verde was within the sphere of influence of (and connected by road to) the great religious and trading center at Chaco Canyon in northern New Mexico. For reasons that are still unclear, Chaco went into decline and was abandoned by the late 1100s. As Chaco was declining, Mesa Verde – perhaps because of its more defensible location some 2,000 feet above the valley floor – grew in population and the multi-storied buildings we see today were constructed. Then, in the late 1200s, within a generation or two, the Ancestral Puebloans at Mesa Verde and elsewhere left their homes, moved south and east – perhaps drawn by religion – and gradually became assimilated into the Zuni, Hopi and Pueblo cultures that survive today throughout Arizona and New Mexico.
Like the structures at Chaco Canyon, Mesa Verde exhibits distinctive features of the Ancestral Puebloan culture, such as T-shaped doorways and round kivas used for religious ceremonies and perhaps for many other purposes. The kivas were once covered and had small outlets to allow smoke to escape.