Excavation of a Portion of the East Ruins, Aztec Ruins National Monument, New Mexico


Save for one pine specimen, a beam from upper Room 12, all other wood found in Rooms 8-14, 24, and the kiva over Room 1 was juniper. Numerous sections were submitted to the Laboratory of Tree-Ring Research at the University of Arizona. Thus far the only date obtained came from the pine beam. Dr. Bryant Bannister reported that "the date is definitely a cutting date and the tree was felled very late in the summer of A.D. 1240" (personal communication, June 4, 1962).

In 1940 Deric O'Bryan took tree-ring samples from both the West and East ruins at Aztec. This material was dated at Gila Pueblo by means of measured rings, and later the same year, Harold Gladwin submitted the results from both pueblos in a letter to then Custodian Carroll Miller of Aztec. The dates for the East Ruin are in Table III.


Cell Count
No. Inside



(1) Wall north of central kiva (probably Room 5).
(2) Outside room, north of central kiva (Room 22).
(3) North room of tier E of central kiva (Room 2?).
(4) Central room of tier E of central kiva (Room 3?).
(5) South room of tier E of central kiva (Room 4?).
(6) 2nd room from east, outside (vicinity of Room 8).
(7) 2nd room from east, outside (vicinity of Room 8).
(8) 2nd room from east, outside (vicinity of Room 8).

With the same letter, Gladwin submitted dates for the West Ruin. These for the West Ruin showed a concentration of 74 dates between A.D. 1106 and 1121, and three dates at 1225-1252. The East Ruin, Table III, shows five dates at 1116-1120 and three dates at 1236-1239. Gladwin believed that the dates between 1116 and 1120 from the East Ruin came from reused timbers taken from the West Ruin. His letter says in part,

"I am delighted that we can give dates of 1236 to 1239 for the East Pueblo. You will see that 5 pieces of wood show that they were taken from the main ruin and reused when the East Pueblo was built. It is also noteworthy that the only 7 pieces of juniper in our entire Aztec collection came from the East Pueblo."

In 1934 Harry T. Getty took borings from several rooms from which he derived dates for Rooms 22 and/or 23 identical with those derived 16 years later by Gila Pueblo. (Both Gladwin's and Getty's letters are in the files of the Aztec Ruins National Monument.)

Data presently available from the East Ruin reinforces Gladwin's opinion that construction took place in the 13th century and that dates in the 1100's came from reused timbers from the earlier West Ruin. The earlier dates are not in accord with the recently derived date of A.D. 1240, and they are not in agreement with the ceramics nor the architecture as they are now known. Compared with the ceramics, the earlier dates would seem to say that a portion, at least, of the East Ruin was built some 80 years before Classic Mesa Verde pottery reached its flower, and at a time when Chaco Black-on-white was in vogue. Ninety-two percent plus of all black-on-white sherds derived from work in the East Ruin are Classic Mesa Verde Black-on-white. The remainder, of Chaco or Morris' Chacoesque and Mancos and McElmo, show up in the East Ruin either as intentional fill derived from refuse or as spall material from wall construction.

Since the Classic stage in Mesa Verde pottery was reached in the 13th century, it is more reasonable to believe that the East Ruin was built after 1200 than before. Hence, the dates 1236-1239 seem more in line; but there is no assurance that even these are not also from beams which represent salvaged material. By 1250 the majority of the large pine beams had been in place in the West Ruin well over 100 years. And it is probably more than coincidence that all except one of the main beams and secondary roofing material in Rooms 1, 8-14, and 24 of the East Ruin are of juniper. When these rooms were built, it is quite possible that many of the sound beams in the West Ruin, other than those which were still in use, had either been salvaged, burned, or were, by their position in refuse-filled rooms, so difficult of access that the people were resorting to the readily available wood then growing in the immediate vicinity. Furthermore, there are some grounds for believing that the population had been depleted or weakened to the extent that timber expeditions for large pine logs involving a sizable, perhaps specialized, labor force, and considerable time, were either out of the question or no longer deemed worth the effort.

Initial source of wood is problematical. Conceivably, large beams could have been floated down the Animas, if the Aztec vicinity did not then support stands of pine, pinyon or fir. We have implied that some large conifer beams in the East Ruin are reused timbers, salvaged from the West Ruin, and that the predominant juniper found in Rooms 8-14 was obtained from the immediate vicinity of Aztec.

On the evidence to date, the East Ruin is a pure Mesa Verde site, not preceded by Chacoan occupation, built and occupied in the 13th century. If anyone was living in the West Ruin at this time, they too, were Mesa Verdeans rehabilitating parts of what was initially a Chacoan structure. In a short span of 50 years, from 1250-1300, they became a disintegrating, disorganized, and diminishing lot. There is some evidence that they were moving out of the San Juan at this time, probably in small groups, to the south. One migratory Mesa Verde group can be spotted in Canyon de Chelly at A.D. 1284 (Morris 1941: 227-230). Another may be noted in the Chacra Mesa east of Chaco Canyon (Vivian 1959: 74-77). Perhaps they were enroute to their assumed final homeland in the Rio Grande district. It is worth noting also that recent excavations by Hawley (1961: 3) in connection with Pueblo land claims and her correlative studies of Keresan oral traditions are strengthening Mera's hypothesis (1935: 39) that the Keres language, particularly Acoma and Laguna, and Mesa Verde pottery might be parts of the same culture.

Frankly, I do not know in what year the East Ruin was deserted. A reasonable guess would be near the close of the 13th century. But I would place complete reliance on dates from the fresh-appearing juniper beams in Rooms 8-14 if they could be obtained; barring this, a great amount of carefully recorded excavation in undisturbed portions of both mounds of the East Ruin will be necessary before further refinement of dates is possible. While there may have been short intervals of construction and rehabilitation at the East Ruin, I would place the initial construction date after 1200, at least for those rooms covered in this paper, and the cultural florescence at about 1240.


Stratigraphic data for the kiva over Room 1, and upper Rooms 9 and 11, appear valid and reliable. While material in the fill of upper Rooms 12 and 13 may have been redeposited, partly in the modern period, it nevertheless appears representative of the site thus far uncovered. Contents of upper Room 14 should probably be discounted.

According to Morris, who had tested down to sterile soil, the East Ruin is a Mesa Verde great house (Montezuma Phase) which has a Chacoan base (Mancos-McElmo Phases) only in the sense that there are no Chaco sherds beneath the East Ruin except in what was surface soil before the building was erected (1939: 40).

At the West Ruin Morris proved conclusively, not once but many times, the existence of a sterile layer representing a gap or period of abandonment between the initial Chaco occupation and the subsequent reoccupation by the Mesa Verde Branch (1928 passim). This was corroborated by Vivian at the Hubbard Mound, where he too found a sterile sandy layer signifying hiatus or abandonment of unknown duration between the first two construction levels (Mancos ? McElmo Phases) and ??? the third and final erection of the tri-wall building (Montezuma Phase) (Vivian 1959: 53).

The implication of Morris' work at the East Ruin, therefore, is that while people of the Chaco Branch were undoubtedly using the area now occupied by the East Ruin for either agricultural or other pursuits, they were not responsible for erection of the East Ruin itself. That Chaco buildings may somewhere underlie the vast East Ruin is not denied. From present evidence, however, these possibly existent buildings of Chaco origin are neither linked structurally nor culturally with the East Ruin as they are in the West Ruin.

According to the best available evidence, fully developed Mesa Verde Black-on-white was present in the La Plata by A.D. 1176, and was brought to the Aztec vicinity no earlier than 1171 (Morris 1939: 214). Initial construction of the West Ruin occurred between 1110-1121 and Mesa Verde pottery does not appear in this first occupation.

While both Morris and Kidder (Morris 1939: 203; Kidder 1924: 6) agree that the West Ruin was a Chaco-inspired structure, Morris modified his view somewhat in regard to ceramics, feeling there was a definite lag north of the San Juan compared with the Chaco area, and that this lag was more pronounced in ceramics than in architecture: "Not ??? withstanding, pottery made and used by the builders of Aztec ruin [West Ruin] is more Chacoesque than Chaco. It is more Chaco, certainly, than anything else, but there is little of the clear white slip and the beautifully executed, narrow-line hachured patterns that are conspicuous features of the highest Chaco wares. It is representative of the black-on-white ensemble that was in general use north of the river at the time when the best wares of the Chaco center were being made, and I believe is the result of local expression of the generalized Chaco urge far more than of direct influence from the Chaco itself" (Morris 1939: 205).

If some of this Chacoesque pottery may be equated with Mancos Black-on-white, and McElmo Black-on-white considered as the nascent stage of Mesa Verde Black-on-white, few students could quarrel with the thesis that two successive cultural forces, Chaco and Mesa Verde, are discernible at Aztec.

Use and Abandonment

The kiva over Room 1 lacks the pilasters normally associated with the Mesa Verde kiva, but must nevertheless be considered a ceremonial chamber. Room 1 below the kiva was not excavated. Its walls are not smoke-stained, and we can only assume that it was a sleeping or storage room.

Lower Rooms 8, 9, 12, and 13 (plate 24) show such little wear or usage, that their purpose is uncertain. Floors were clean, there were no firepits or fired areas, and the walls and ceilings are not smoke-stained.

PLATE 24—General view to the northwest showing Rooms 11, 12, 13, 14, and 24 at completion of the 1957 excavation-stabilization program. Rooms 8 and 9 are obscured from view and lie at the far side of the cluster.

Lower Rooms 11 and 14 are moderately smoke-stained, yet contain no firepits. They were, however, close to the firepit in the floor of Room 24 to the south, and this is the only visible source from which the blackening of walls may have occurred. Juniper pole sills of doorways, though shiny in some cases, are not worn from usage. From the evidence, or lack of it, one can only guess that lower Rooms 8 through 14 were either storage or sleeping chambers.

Room 24 is the only one showing considerable use. The floor was dirty and stained by fire, and the central firepit nearly full of ashes. Very probably subfloor tests in Room 24 would disclose additional floors. A fragmentary second-story floor also showed a fired area but without firepit.

Upper Room 8 was excavated by others and we have no data on it.

Upper Room 9 was apparently emptied of contents when abandoned, if indeed it was ever used, and remained undisturbed thereafter. A used, fired floor area was on the roof but any evidence of a permanent or temporary structure, if formerly present, had been destroyed.

Upon abandonment, upper Room 11 was used as a trash area, since it contained 3 feet of mostly dry vegetal matter, byproducts of agriculture.

Upper Rooms 12, 13, and 14 were intentionally filled, the last containing upwards of 5,000 sherds. The pottery was from A.D. 1200-1300, mixed with only a few broken and discarded artifacts, while the former two rooms contained little other than earth mixed with Mesa Verde Black-on-white sherds.

The impression is strong that upper and lower Rooms 8-14 and 24 were little used, that abandonment was premeditated and without haste, and when this occurred little of value was left behind. Whatever may have been the reasons, they do not appear to have been of catastrophic proportions, such as a sudden attack by enemies. Neither is there evidence of burned sections in the site such as may be seen in the extensive, fire-gutted areas of the West Ruin. The most acceptable cause for abandonment is the disastrous and far-reaching drought of A.D. 1276-1299.

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Last Updated: 10-Jan-2008
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