Man in the San Juan Valley

THE AZTEC PUEBLO. (continued) In the midst of the populous Animas Valley, along the edge of an old river terrace, early in the 1100's a large multistoried stone pueblo was built in an architectural style reminiscent of that in Chaco Canyon. Did a large migrant group from the Chaco area—or some other area where Chaco-like people were living—move into the Animas Valley and erect this structure? Or did some of the local citizenry decide to join in a community effort and copy the building techniques of their neighbors to the south? If so, what was the impetus which launched the local people upon this ambitious project? Perhaps a small group of highly skilled technicians, under the leadership of a few "priests" or medicine men came from the Chaco area into the Animas Valley. Once established there, by persuasion, teachings, or by religious magic and psychological control, they may have prevailed upon some of the local population to join them and to build their homes and kivas of sandstone blocks, in the traditional Chaco style.

We may never know the exact answer to these questions, but wherever the people came from, whoever they may have been, whatever the guiding impetus, Aztec pueblo, like Rome, was not built in a day. Dates from tree rings—as described later—indicate that the pueblo was built between A.D. 1110-1124, with the major construction periods in 1111 and 1115. Probably a small group, or just a clan, moved into the site about 1110, and finding it suitable for habitation erected the first small part of the pueblo. The next year a much larger group, perhaps several clans or more, joined the earlier settlers and more than 50 percent of the pueblo was finished. Then, in 1114 or 1115, a third wave of migrants arrived and essentially completed the pueblo, except for the one-story row of rooms which closed off the south side. It is possible that some of the indigenous Animas population joined these newcomers and moved in with them. From 1115 until about 1124 or 1125, occasional rooms were added as new quarters were necessary for newly married couples and as old rooms were used as refuse dumps.

To the northwest of the ruins, less than 2 miles away, the Indians found an outcropping of sandstone which could be broken into shape and then ground into rectangular blocks. These were hauled to the proposed building site, where the women took over the construction. Holes were dug in the clay soil nearby, water poured into them, and then stirred to produce a thick adobe mud. This was used, along with crude unshaped sandstone blocks, as filler for the walls. On the outside, the women laid up the well-shaped blocks in regular courses, chinking them with small spalls or potsherds.

The rooms were laid out in rows adjoining one another—as one row was finished, another was added alongside of it. When several rows had been completed, second and possibly even third stories were added. The first group to arrive probably completed the major part of one wing; later groups added to this and erected the other wings and associated kivas until the entire pueblo had the traditional planned aspect of a typical plaza-enclosed Chaco pueblo. In the central plaza area several kivas were dug and roofed over at ground level. The fourth side consisted of a single row of one-storied rooms. Finally, even a fourth story may have been added in places. Sometimes a large square space was temporarily left open, later to be filled by a circular kiva.

Out in the plaza, during the latter part of this first occupation, work started on the Great Kiva, for this was the center of the ceremonial life of the entire pueblo. Here would be performed the ceremonies which would insure the inhabitants that theirs would be a long and happy life and that everything would prosper for the new community.

For roofing the rooms, main stringers of pine or juniper were used, and over these were laid splits of juniper or long poles of cottonwood. Next came a layer of rush or reed mattings and then a layer of dirt and adobe which formed the top of the roof, or the floor of the room above if there was more than one story.

The pine logs used for the main stringers are good-sized, many being 1 foot to 1-1/2 feet in diameter and up to 10 or 12 feet long. Although juniper is still fairly abundant in the nearby country, good stands of pine today are many miles away. At the time the first parts of this pueblo were constructed, the pine forest may have been much closer. Perhaps extensive cutting hastened soil erosion and thus caused the forest growth to retreat.

Prehistorically it still was a long haul to bring in such big logs. Many people have assumed that the logs were floated down the Animas River. This would have been the easy way of doing it, but the logs found in situ in the ruins were obviously fresh cut, peeled while green, and show no scars. They must therefore have been carried overland from their source, no matter how far away, for it would have been impossible to float them downstream with out being scarred and bruised in transit.

Through the growth of tree rings on pine logs, it is possible to date the time at which they were cut. If a tree is cut today, the outermost ring constitutes its growth for the year in which it is cut. Counting toward the center of the tree ring by ring, you will arrive at the date at which the tree was a young sapling. Climatic factors, dry and wet spells, are reflected in the width of the rings. Dry years usually show small, odd-shaped or stunted rings; normal years show regular well-shaped rings, and extremely wet years may result in excessively large rings. These various rings, which are arranged into patterns, can be matched with similar tree-ring patterns from still older trees, and a chart of patterns can be prepared which will extend as far back in time as you can find specimens with overlapping patterns. Against this master chart the ring pat tern of any particular tree can be compared and the specimen dated. Today archeologists have such a tree-ring master chart which extends back to the time of Christ for the San Juan area.

At Aztec, samples of tree rings were secured from some of the beams that still existed at the time this dating process was discovered. Such samples fall into two groups of dates. One group (with numerous samples) was placed between A.D. 1110 and 1124; the second group (with only six samples) between 1225 and 1252. The tree-ring dates indicate that the great pueblo at Aztec had undergone at least two major periods of construction. Since a large number of dates range from 1111 and 1115, this would appear to have been the first peak of building activity.

It is possible that earlier samples have rotted away or have been destroyed by later Indians or by the early white settlers. Moreover all building activity probably did not suddenly cease in A.D. 1124; it may well have continued for another 10 years, but the beams representative of this later period have since been destroyed. We can safely say that the first construction period at Aztec pueblo occurred sometime between 1110 and 1130, with most of the development occurring around 1111 and 1115. Likewise, a second major construction period at Aztec occurred sometime between 1220 and 1260, with major development in the 25-year span between 1225 and 1250.

The two construction periods at Aztec, as indicated by the tree-ring dates, are corroborated nicely by other evidence found by Morris that Aztec actually was built by one group of people, abandoned and then reoccupied at a later date by a slightly different group of people. Throughout all the rooms he dug, he found sterile layers of windblown sand and ruined debris from falling walls and ceilings. In this debris and under the sand he found Chaco-like pottery and artifacts. In addition there were surprisingly few burials. The last point might seem strange, except for the fact that even today, 40 years after Morris' work and despite endless searching, archeologists have located few Chaco-type burials in Chaco Canyon itself. Whatever the burial customs of the Chaco people may have been, they have eluded archeologists for many years. The absence of burials of this period at Aztec is a clue that probably a group of Chaco-like people, bearing the distinctive Chaco culture, may actually have moved into the Aztec area.

Morris wrote that he found many rooms built in typical Chaco-style architecture. Granting that the local sandstone was not quite as easily worked as that at Chaco, the large-size rooms, the high ceilings, the banded-veneer masonry walls, the large doorways, and other techniques used were very similar to the architectural techniques of the Chaco area.

Overlying the Chaco debris and sterile sand layers, Morris found pottery, household utensils, and burials characteristic of the classic Mesa Verde Period—a period which occurred later than the great Chaco Period. In addition, there were obvious architectural signs of rebuilding and remodeling within the pueblo. Large Chaco-type rooms had been made smaller by wattle-and-daub partition walls, while doorways had been shortened and narrowed more like the ones at Mesa Verde.

Thus there were two definite periods of occupation at Aztec, one by a Chaco-like people and one by a Mesa Verde-type people. The two major construction periods, as indicated by the tree rings, agree with Morris' evidence of two occupation periods and, so far as we know, closely date those periods during which the pueblo was actively inhabited.