Man in the San Juan Valley

THE AZTEC PUEBLO. (continued) However, it is the large multistoried pueblos of the Chaco Canyon and the great cliff dwellings of the Mesa Verde that attract the most attention. The native sandstone at Chaco Canyon made an excellent building material—it was easily obtainable, it factured along natural cleavage planes into thin slabs, and it could be ground and pecked into large rectangular blocks. Both the availability of sandstone and the relative ease with which it could be worked were important factors in developing the Chaco style of architecture.

Some of these pueblos may have been as high as five stories; most were at least three or four stories. All show signs of constant alteration in individual rooms and in their general layout, as though some feverish urge was forcing the people to keep shifting the arrangement of their dwellings. Not all the rooms in any of the large pueblos were occupied simultaneously; usually the rooms toward the rear were used for storage or, in many cases, as dumps for refuse and garbage. Occasionally, burials are found in them.

All the great Chaco pueblos form self-contained units—that is, they were built around central plazas or courtyards, as in the case of Pueblo Bonito, with a low row of single-storied rooms closing off the formerly open side of the plaza, or they were roughly rectangular with closely knit contiguous rooms and internal kivas as in Yellow House. This closure, plus the fact that the doors and windows which formerly had opened outward at the rear or sides are now sealed up, has led many people to believe the later parts of this period were marked by trouble and strife and that this self-containment was a defensive measure.

At Chaco Canyon, many parts of the pueblo walls were finely made. Different styles of decoration were produced by using sand stone blocks of various sizes. An unusual effect was achieved by alternating bands of large rectangular blocks with a series of bands of much smaller, finely laminated sandstone blocks, The interior of the walls consisted of crude rubble in adobe mud, and, where some form of banding technique was not used in the outer or veneer wall, the chinks between the larger stones were filled with adobe mud and spalls or very small chink stones. When carefully done, this technique also produced an attractive appearance. Since both the interiors and exteriors of walls were usually plastered with numerous thin layers of adobe, it is something of a mystery why the Indians took the trouble to produce such pleasing effects in their stone work and then to cover it up with plain plaster. It may be that what we regard as decoratively charming was to them simply a structural and engineering feature. They may have considered carefully spalled and banded masonry to be structurally sounder than simple rock, rubble, and plaster walls. Usually the walls of the upper stories are successively thinner, and a similar idea was used in the beams which form the room ceilings (and thus the floors of rooms above)—the heaviest beams were in the lower rooms, and those in the upper stories were correspondingly lighter and smaller.

In the Chaco-type great pueblo of this period, the majority of the rooms were large by pueblo standards. They were rectangular in shape (except for the kivas, which are circular) and often 8 to more than 12 feet long and 6 to 8 feet wide. Ceilings were 8 or 10 feet high, and doorways, usually with a raised sill, were 3 to 4 feet high and 2 to 3 feet wide. In comparison with the typical rooms in the Mesa Verde area, those in Chaco were very spacious.

In the Mesa Verde region the people were also learning to build in sandstone, but the available sandstone was coarser than that in Chaco and did not have the clean fracture planes, and the masonry was of a thicker and seemingly cruder sort. Walls were made of rectangular blocks of tan sandstone which quite often were carefully shaped and ground to give a pleasing effect.

On the sloping green tabletop mountain, known as the Mesa Verde (from which the surrounding area gets its name), in the early part of this period (A.D. 1050-1200), the people built large unit-type pueblos upon the long finger-like mesatops which extend southward from an abruptly rising escarpment on the north. Most of these units were multistoried, and although they centered around a central plaza, they were much smaller, more tightly contained units than their Chaco Canyon counterparts of the same period. Frequently they contained at least one towerlike structure connected by an underground passage to a nearby kiva. One or more other kivas might be located in, or front on, the small central plaza.

Although the rooms are smaller than the ones in the great communal houses of Chaco, they are solidly built of double course sandstone blocks. Because in most cases the mesas are sloping southward, many of these unit houses were built upon one or more terraced flats. Frequently the only entrance into the pueblo was by staired entranceway leading from the south into the small interior court or plaza.

At Mesa Verde, in the latter part of this period (about A.D. 1200-1225), the people who had been living on the mesatops in the unit house type of dwelling seem suddenly to have abandoned these dwellings and taken up residence in the nearby caves. Here they built great pueblo-type structures, often of several hundred rooms with numerous associated kivas. Since they were limited by the ceiling of the caves to two and three-story structures, and not so exposed to the elements, it was not necessary to use such thick, strong walls, roofs, and ceilings. The general construction at Mesa Verde was therefore thinner than at Chaco, and the rooms and doorways are considerably' smaller. In fact, with the warm southern exposure of the caves which were used, the people must have done most of their living and daily chores outside, in the small plaza areas and on the roofs of the lower tiers of rooms. The rooms themselves could be small, for they were probably used only for sleeping and storage. Because the native sandstone at Mesa Verde is coarser grained and does not fracture as easily into blocks and spalls, the style of alternating large and small banded masonry found at Chaco was not adopted there. But much of the stonework at Mesa Verde is nonetheless excellent; perhaps some builders had greater artistry than others, for some of the rooms, especially the circular towers, contain blocks which have been carefully pecked, ground, polished, and fitted into exact position with loving care.

In this period, also, a structure known as a Great Kiva comes into prominence. It usually has an entrance on the north side (instead of through the smoke hole), often with a stairway. It has a large raised firebox in the center of the south side, and occasionally another entrance there. In addition, on the east and west sides of the floor are large, rectangular stone-lined pits, built up above the floor. Their exact use is still a mystery, and perhaps they served more than one purpose. It has been suggested that when covered with boards, they would make excellent foot drums for the dances, or good places for the medicine men to conceal themselves while performing certain magical rites during initiation ceremonies. Finally, four large posts set into the floor of the kiva supported the roof. Great Kivas are fairly common in the Chaco area, but in the Mesa Verde vicinity they seem to be very rare.

In each of the two areas mentioned above—Chaco Canyon and Mesa Verde—archeological work has revealed a continuous occupation of the sites and the immediate vicinity. At the great Aztec ruin, however, there is still some doubt as to what really happened. In two different time periods there seem to be strong architectural relations to both the Chaco and Mesa Verde centers, as well as close ties in ceramics and other items of material culture. Part of the intriguing mystery at Aztec is whether these similarities represent actual migrations from those centers on a fairly large scale, or an exchange of ideas, or small groups of migrants who strongly influenced the local population.