In fact, it could better be proposed that some of the first groups, which had to leave Chaco Canyon about 1100 because of the incipient arroyo and its accompanying loss of irrigation water and generally lowering water table, might actually have moved to the Animas and established Aztec. Perhaps a rather coincidental event may have occurred at Aztec which caused its abandonment just as Chaco Canyon was almost depopulated. The early settlers in the Animas recall evidence of a prehistoric canal flowing along the lower slopes of the terrace to the north of Aztec Ruins, somewhat lower than the modern one. This canal took off on the right bank of the river, several miles upstream from the pueblo. A major shifting of the river, a swing of the main stream against this old river terrace on the right bank, would have effectively cut the canal at a point below which the people could not take off water to irrigate their fields and in a manner they could not repair. Such a disaster would have forced them to move to other cultivable fields; if none were available nearby (and they may have all been taken up by other local groups), they would have had to go far away. They couldn’t return to Chaco Canyon or other areas near there, for these places too were being depopulated. So perhaps they followed some of their Chaco kinfolk who were intermittently migrating in groups to the Rio Grande, or to the Hopi country. In these new areas, mixing with the local population, they lost their distinct cultural identity. We can look at the modern Pueblo Indians of today and wonder if perhaps some of their long ago ancestors may not have actually lived at Aztec or in Chaco Canyon. [Illustration: A pottery “kiva” jar. Mesa Verde style. Diameter at mouth, 4½″; Maximum diameter, 13⅓″; Height, 9½″.] But there is a double mystery at Aztec: as indicated earlier, overlying the evidences of a Chaco-phase occupation, Morris found evidence of rebuilding and rehabitation of many rooms. Large-sized Chaco rooms had been shortened, reduced, or cut off by interior walls and lowered ceilings. Older doorways had been blocked up, or had been partially filled and reduced in size. In some cases entire small rooms, complete with ceilings, had been built within larger rooms. New floors had been laid down upon the debris and windblown sand which partially filled some of the older rooms. Older beams had been pulled out of rooms and reused elsewhere, or new walls in a different style had been built in place of those that had collapsed.