Various theories have been advanced to explain this exodus: soil erosion, warlike enemies, poor facilities for urban sanitation, drought, and intervillage warfare. One or a combination of these factors might have been instrumental in bringing about the abandonment of the region.
Aztec Ruins National Monument
Aztec Ruins National Monument, at Aztec in the northwestern corner of the state, was set aside to preserve an outstanding example of classical Pueblo construction, one of the largest pre-Spanish villages in the Southwest. More than 40,000 visitors come to the Monument each year.
Tree-ring dates indicate that most of the big central pueblo was rapidly constructed during the period 1106 to 1121. At this time, the people of Aztec were influenced by the cultural center to the south, Chaco Canyon. During the last half of the 1100’s, after the decline of Chaco Canyon had begun, the people of Aztec began to look toward the north, and by 1200, Mesa Verde ideas dominated the region. Aztec was abandoned by about 1300, as was the rest of the general region.
Of particular interest at Aztec Ruins National Monument is the reconstructed Great Kiva. The Pueblo Indians built separate rooms, now known as kivas, for ceremonial purposes. During the period of Chaco influence, the people at Aztec constructed a very large circular building, 48 feet in diameter, in their plaza. Its features differ from those of the small kivas and establish it as a Great Kiva, similar to those at Chaco. The Great Kivas represent the peak of religious architecture among the Pueblos. The Great Kiva at Aztec was completely restored in 1934 by Earl H. Morris, of the American Museum of Natural History.
Bandelier National Monument
Bandelier National Monument, forty-six miles west of Santa Fe, preserves the ruins of dwellings and other structures that were erected by Indians who lived in the area until about 1550 A.D. Almost 100,000 people visit the Monument each year.
When many of the ancient Pueblo Indian centers were abandoned in the late thirteenth century, the people moved to locations where the water supply was more constant. A favorable area was the upper Rio Grande Valley in what is now New Mexico. One of the later flowerings of Pueblo culture occurred here. The ruins within Bandelier are representative of this phase of Pueblo development.
In Frijoles Canyon, the Indians chose the location of their homes well. The creek that runs through the canyon flows all year. On the canyon floor and mesa top there was land suitable to the cultivation of crops. And the canyon walls of soft tuff (consolidated volcanic ash) could easily be hollowed out by the Indians with their harder stone tools in fashioning storage rooms behind dwellings built against the cliff.
Cliff ruins, or talus villages, extend along the base of the northern wall of the canyon for about two miles. Other ruins are located on the floor of the canyon. The houses of stone masonry were irregularly terraced, from one to three stories in height. Some hollowed recesses at the base of the cliff also were used for dwelling rooms.