Aftermath: The San Juan Basin

Huerfano Mesa from Peñasco Blanco

Ever since 1927, when it was established at the first Pecos Conference, the so-called “Pecos Classification” has been the most popular system of chronology used by southwestern archaeologists.  This is actually rather odd in some ways, since the classification was developed before absolute dating based on tree rings was totally secure or well-established, and as a result the “periods” it uses are (or at least originally were) based mostly on material culture and organized into a sequence that implied a steady process of “progress” or evolutionary development, with the pithouses of the Basketmaker Period giving way to the small aboveground pueblos of Pueblo I, then the larger but scattered small house sites of Pueblo II, culminating in the “Great Pueblos” of the Pueblo III period: the major aggregated sites that are the best-known examples of prehistoric pueblo architecture.  (The Classification continues past Pueblo III, but my concern here is with these early periods.)

Once absolute dating became more secure, however, problems with the classification began to emerge.  Most importantly, perhaps, tree-ring dates established conclusively that the great houses at Chaco Canyon, considered among the finest examples of Pueblo III architecture, were actually considerably earlier than the other “Great Pueblos” at places like Mesa Verde and Canyon de Chelly.  Indeed, the Chacoan sites were contemporaneous with the small sites throughout the region that the classification put in the Pueblo II period.

T-Shaped Doorway at Salmon Ruin Sealed with Cobbles

Interestingly, however, while some archaeologists used these and other problems as reasons to stop using the Pecos Classification, most did not, and instead modified the classification in various ways to incorporate new understandings.  Some reinterpreted the developmental categories as applying to sequences that were similar throughout the region but took place at different absolute times in different areas; thus, Chaco becomes a place with an unusually early transition from Pueblo II to Pueblo III.  Others did away with the evolutionary aspects of the system entirely and redefined the periods as purely chronological.  Under this adjustment, Chaco becomes one development during Pueblo II.  One drawback to both of these approaches is that they tend to be applied differently in different regions, since the relationships between absolute time and material culture vary considerably throughout the southwest.

Line of Doorways at Aztec Ruins National Monument

The authors of the different chapters in The Prehistoric Pueblo World, which is devoted to the Pueblo III period but, interestingly, avoids the use of that term in its title, use a variety of means to deal with this issue.  Most retain some version of the Pecos Classification, whether as a series of developmental stages or merely a sequence of arbitrary absolute dates.  Some, however, refrain from using the Pecos terminology and substitute other systems, whether because the version of the Classification generally used in their region conflicts with the time frame used to organize the book or because they have more fundamental problems with the Classification.

The most prominent example of the latter approach comes in Chapter 8, by John Stein and Andrew Fowler.  Stein, of the Navajo Nation Historic Preservation Department, is noted for his contrarianism on a variety of subjects related to southwestern archaeology, but he has also made many important contributions to general understanding of certain parts of the ancient southwest, and both these characteristics are on full display here.  The chapter is on the San Juan Basin and its peripheries, which is the region where Chaco Canyon is located, and it thus deals heavily with the Chaco Phenomenon and its aftermath.  Stein and Fowler acknowledge at the beginning that this book is not about Chaco but they argue that a full understanding of their area in the post-Chaco period requires them to address the Chaco system and its nature.  They also argue equally forcefully that the origins of the Pecos Classification give it a considerable amount of interpretive baggage that makes it more problematic than useful, and they therefore eschew its use even as a series of arbitrary segments of absolute time.  (They are not totally successful at this, actually, and there are a couple of places in the chapter where they slip into using Pecos terminology.  They mostly manage without it, though.)

Light Snowfall on Fajada Butte

One of the main problems Stein and Fowler point out about the Pecos Classification is its near-total emphasis on residential architecture, and its consequent tendency to interpret all architecture, including that of Chacoan great houses, as primarily residential.  This is particularly problematic given the curiously limited evidence for residential use of great houses, despite their size, and Stein and Fowler are quite adamant that great houses are not residential structures at all.  Rather, they see them as community integrative architecture, and divide the overall Anasazi architectural tradition into three categories:

1. Residential, or household-level, represented in the earlier periods by small-house sites
2. Community integrative, represented during the Chacoan era (and in some regions in the immediate post-Chaco era as well) by great houses
3. Regional integrative, uniting communities throughout a region, represened in the Chacoan era by the Chaco Canyon complex and during the post-Chaco era by the Aztec complex

Line of Interior Doorways at Aztec Ruins National Monument

Importantly, Stein and Fowler see these three types of architecture as originating from the same general cultural background and varying primarily in scale.  They also see them as evolving uniformly over the period of Anasazi occupation of the San Juan Basin, with both residential small houses and integrative great houses being regularly replaced in accordance with a long-term progression of “ritual time.”  Perhaps most controversially, they see the “collapse” of Chaco and the contemporaneous rise of Aztec in the early twelfth century as merely a replacement of this sort, albeit on a much vaster scale than seen elsewhere in the sequence.  Since they don’t see the great houses as reflecting population numbers in any meaningful way, they disagree with the common interpretation of this change as indicating a decline of either population or ideology, instead seeing it as a planned regional reorganization.  They even argue that people continued to live in small sites for quite some time after the last reliably dated small houses at Chaco, proposing that for some reason dwellings in this period were much more ephemeral and thus have not survived in the archaeological record.

I find that last part, in particular, extremely dubious, and I’m not entirely sold on any of this.  I think the most important contribution this chapter makes, however, in addition to the data it presents on post-Chacoan sites in its region, is in making such a strong argument against great houses being residential “pueblos” in the sense envisioned by the original Pecos Classification.  While I’m more open to the idea that at least some people lived in the great houses for at least some part of their history, I definitely think it’s difficult to argue, given the evidence available, that they were ever primarily residential or had high populations comparable to those of later aggregated pueblos.  For that reason alone I find this chapter important and useful.

Reconstructed Great Kiva, Aztec Ruins National Monument

Otherwise, I’m skeptical.  In some ways this sort of “ritual time” construction is clearly intended to counteract some of the cruder environmental-determinist models that try to explain all the changes in southwestern prehistory as reactions to changes in the environment, and it’s certainly true that some of those models go too far in that direction, but by the same token it seems just as implausible, if not more so, to totally disregard the possibility of external influences on culture change the way Stein and Fowler do here.  Surely there was a certain amount of planned, regular renewal of ritual facilities and other community integrative structures, and there is actually quite a bit of clear evidence for this at least for great kivas, but just as surely climatic conditions did fluctuate, and in an environment as marginal for agriculture as the southwest in general and the San Juan Basin in particular those fluctuations must have had some effect on the decisions of a primarily agricultural people living in that area.

So I remain interested but skeptical, which is my general attitude toward strikingly contrarian interpretations.  I do think they’re very useful in stimulating discussion and directing research toward important unresolved issues, so I have no intention of trying to stop them from being proposed, but I have a hard time accepting any of them completely.  In the case of Chaco in particular, these theories are both numerous and mutually contradictory, which adds another reason for both interest and skepticism.  Bring them on, I say, but I remain unconvinced.

Chaco Street in Aztec, New Mexico

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Dentistry

Montezuma Castle

Christy Turner of Arizona State University is one of the most prominent and respected physical anthropologists of the prehistoric southwest, and at the same time a controversial figure on account of his divisive theories about cannibalism in the southwest and its relationship to the Chaco system.  I will have more to say about that in subsequent posts.  Here, however, I’m just going to note a recent article of his on a less contentious (but still quite interesting) subject: dentistry.

The article begins with a story about how another physical anthropologist had asked him in 1995 if he knew of any cases of drilled teeth in the prehistoric southwest.  That anthropologist, Tim White of Berkeley, had found a drilled tooth at a Fremont Culture site in northern Colorado and was trying to figure out what to make of it.  Turner replied that he didn’t know of any other examples, and White went on to conclude that the tooth had apparently been drilled for therapeutic reasons, presumably to relieve pain, although the exact source of the pain involved was not clear from the surviving remains.

Years later, however, Turner was looking through his files and realized that he had in fact seen another example of a drilled tooth.  It was found in the jaw of a young woman buried at a site in Sycamore Canyon, Arizona, quite close to Montezuma Castle National Monument, in 1965.  Turner examined the tooth in 1986 while doing research for a project, but had forgotten all about it by the time he talked to White about the subject.  When he rediscovered it he decided to put together an article discussing it to supplement White’s study of the Fremont tooth.

Sycamore Trees at Montezuma Castle National Monument

The basic gist of the article is that the hole drilled in the tooth was right in the same place as an area of severe decay that would presumably be quite painful, making it quite clear that the intent of the drilling was to relieve the pain.  This was the same conclusion that White reached about his tooth, but with the added advantage that in this case the decayed area was quite obvious, whereas on White’s tooth there was no clear sign of similar damage.  Also notable on Turner’s tooth was the fact that the angle of drilling was what would have been the easiest angle to drill from if the woman was opening her mouth wide, implying that the drilling was done during her lifetime rather than after death.  Also suggesting this was evidence of wear around the drilled area from after the drilling, implying that the procedure was at least somewhat successful and the woman was able to go on using the tooth, perhaps with less pain than before.  Turner’s resulting conclusions, while basically similar to White’s, were thus considerably better supported and lent additional credence to White’s interpretations.

What is particularly interesting, however, is that these two teeth are the only known examples of this sort of therapeutic dentistry from anywhere in the prehistoric southwest.  Indeed, Turner states in the article that he is unaware of any other reports of tooth-drilling, ancient or historic, among the natives of the southwest.  This suggests that it is unlikely that this type of procedure, despite its evident success, ever became a widespread practice in the southwest.  Moreover, since the two known instances come from different cultures rather far apart in both space and time, with White’s from the Fremont of eleventh-century northern Colorado and Turner’s from the Sinagua of fourteenth-century northern Arizona, it seems unlikely that there is any connection between the two.  Instead, these are apparently unrelated examples of independent innovation that failed to catch on.

One broader lesson that could be taken from this is that societies don’t continually progress in any particular direction.  There are a lot of odd little things happening all the time in any society, some of which are traditional and some of which are innovative, and while the innovations do sometimes work as well as or better than the traditions, that doesn’t necessarily mean that they will be widely adopted.  Sometimes a drilled tooth is just a drilled tooth.

Dendroglyph on Sycamore Tree, Montezuma Castle National Monument

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Synthetic Addition

Back Wall of Chetro Ketl

Of all the research done over the past hundred years on Chaco, probably the most influential on current views of the Chaco Phenomenon is that done under the auspices of the Chaco Project, a joint effort by the National Park Service and the University of New Mexico to do a wide-ranging, in-depth analysis of Chaco.  The project began in 1969, and fieldwork took place for roughly the next decade.  Administrative and personnel issues kept active fieldwork from continuing any longer, but publication of the project’s results has continued up to the present day.

Most of the publications resulting from the project were monographs and site reports put out by the Park Service, which are important contributions to the literature but are not particularly accessible, both in the sense of being highly technical in nature and in the sense of being put out in limited printings.  Toward the end of the 1990s, however, some archaeologists in the Park Service began to conceive the idea of putting together some sort of general synthesis of the project that would gather together all of the major results in one place.

The ultimate result of the resulting synthesis effort was a book, entitled The Archaeology of Chaco Canyon, edited by Chaco Project alumnus and all-around archaeological gadfly Steve Lekson.  Lekson, who was tasked with planning and organizing the synthesis, decided it was too big a project for one person and instead put it into the form of a series of working conferences on various aspects of the Chaco Phenomenon and the legacy of the Chaco Project.  After these conferences were completed, the results of them were both published separately in various venues and formats and used as the basis for a final capstone conference.  The proceedings of this conference ended up as the basis for the final book, which contains chapters written by the participants summarizing the results of each of the working conferences as well as others by other scholars addressing other topics relevant to Chaco and the Chaco Project.

Casa Rinconada from Below

I’d say that this rather unusual process resulted in a particularly useful volume that gives a solid, up-to-date account of the state of research on a wide variety of Chaco-related subjects, including both those covered in detail by the Chaco Project and others of equal interest.  As Lekson notes in his engaging introduction, however, this is not a coffee-table book.  Rather, it is a synthesis of scholarly research that, while by no means as technical as the literature it synthesizes, is definitely targeted at a readership that is already well aware of what Chaco is and why it is important.  I would definitely not recommend it as an introduction for total beginners; there are other books that are better for that.

For those who do have the necessary background, which I would say is either an awareness of earlier research on Chaco or a general understanding of southwestern archaeology, however, this is a very good way to get a well-rounded sense of what has been happening in Chacoan studies over the past few years and how that research has shaped current understandings of Chaco.  I could certainly quibble with some of the interpretations offered in various chapters, but the nice thing about the multi-author nature of the book is that the authors of the different chapters differ among themselves in their answers to various questions and their interpretations of various pieces of data, so if there’s something in one chapter I don’t like there’s often something on the same topic in another chapter that I find more congenial.

Research continues unabated, of course, and this book is by no means the last word on any of the topics it covers.  The recent discovery of chocolate residue on cylinder jar sherds is just one particularly spectacular (and potentially far-reaching) discovery among many that are being made now and will continue to be made for years and decades to come.  As a summary of data collected and theories proposed as of a particular recent moment in time, however, this book is invaluable and a necessary part of a complete and in-depth understanding of Chaco.

Kiva Pilasters at Pueblo Del Arroyo

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Brilliance

Artifact Made of Scarlet Macaw Feathers at Edge of the Cedars Museum, Blanding, Utah

One of the most exciting developments for archaeology in the past few years has been the increasing application of sophisticated techniques from the physical and life sciences to questions of archaeological interest.  Chemistry has been one of the major disciplines to contribute to this trend through techniques such as trace-element analysis to determine the sources of materials used in artifacts with a precision that would have been unimaginable only a few decades ago, but biology has played a role as well.  One of the most interesting recent applications of molecular biology to southwestern archaeology involves the artifact in the picture above, which I was lucky enough to see in person on my recent road trip.

The artifact (as it is usually designated since its precise function is obscure) consists of a series of yucca-fiber cords covered in scarlet macaw feathers dangling from a piece of squirrel pelt to which is also attached a buckskin strap.  It was found in a cave in Utah in 1954 and is now housed at the Edge of the Cedars Museum in Blanding, Utah, where it is on public display.

It’s really an astonishing thing, mostly because of the near-perfect state of its preservation.  The colors of the feathers are still vibrant.  There were doubtless many items used in the prehistoric southwest that were equally impressive in their brilliant color and fine workmanship, and we occasionally get glimpses of them from fragmented remains, but the perishable materials of which they were made tend to, well, perish over time.  This item, however, happened to be left in a cave, where it lay untouched for 900 years.  Caves are known for their good preservation conditions, and one of the main reasons cliff dwellings have been so important in southwestern archaeology is not that they were ever a major type of settlement in the region (they weren’t) but that they preserve their contents much better than the much more common exposed sites.

This particular item was studied by Lyndon Hargrave, the ornithologist who went on to become a major figure in the development of southwestern archaeology through his work at the Museum of Northern Arizona in Flagstaff.  Hargrave’s archaeological work was wide-ranging and extensive, but he always retained an interest in birds and did considerable research on both remains of birds and artifacts made with bird parts.  In assessing the Utah item, Hargrave concluded that the feathers were from a scarlet macaw, the furry pelt above them from a tassel-eared squirrel, and that the strap was made of buckskin.

The natural range of the scarlet macaw is far to the south of Utah, so it was clear that the feathers indicated some sort of trade connection with cultures to the south.  Whether this connection involved the trade of feathers, live birds, or objects made from feathers was (and to a considerable extent remains) murkier.  Hargrave concluded on the basis of the way the feathers were attached to the cords of the Utah object that they had been attached in Mexico and traded up as manufactured goods.  To his knowledge, however, the tassel-eared squirrel was found only in the US southwest, so he decided that the imported feathered cords must have been attached to the pelt locally to create the full item.

However, since Hargrave’s time new subspecies of tassel-eared squirrel have been discovered in northern Mexico, raising the possibility that the entire item was created somewhere to the south then traded northward to eventually end up in Utah.  To evaluate this possibility, a team of scholars from the Mayo Clinic (Nancy Borson and Peter J. Wettstein), Northern Arizona University (Jack States), and California State University at San Bernardino (Frances Berdan and Edward Stark) teamed up a few years ago to try to apply recent advances in molecular biology to the problem.  Their study, published in American Antiquity in 1998, came to some interesting and fairly definitive conclusions.

Their basic approach was twofold: to reexamine the artifact and evaluate the method of manufacture to test Hargrave’s theory that the feathers were attached to the cords in Mexico and to sample the DNA of the squirrel pelt to see which of the modern subspecies it best matched.  The examination of the item revealed that the feathers were attached in a way that is rather different from that described in ethnohistorical accounts of Mesoamerican practices and more similar to the way feathers were attached to prayer sticks and other items as described in historical accounts of the modern Pueblos.  This clearly implies that the feathering was done in Utah, and that the cords were unlikely to have been important as finished goods.  It still leaves open the question of whether the feathers were imported themselves or plucked from imported birds.  Scarlet macaw remains have been found in various parts of the southwest, including Chaco Canyon, so I find the second option more plausible, but the authors of this study seem to lean more toward the first.

The examination of the object also revealed that the feathering didn’t go all the way up the cords.  The parts of the cords that are under the squirrel pelt are not feathered.  This reinforces the conclusion that the cords were not imported as finished goods, since they seem to have been custom-made for this particular item.

The DNA analysis concluded that the DNA did not precisely match that of any modern subspecies, but it was clearly closest to the northernmost subspecies, the range of which extends into a small part of Utah which happens to contain the cave where the item was found.  This is pretty conclusive evidence that the whole item was made in Utah, primarily of local materials.

So what does this say about Hargrave’s analysis?  Well, it does disprove his theory that the cords were imported already feathered, but it also confirms his theory that the squirrel pelt was local and that the final manufacturing stages were done in Utah.  This may not be the most exciting result, confirming the accuracy of a previous theory, but I think it’s important for the security of the data on which elaborate social theories are built to have these things checked out using whatever techniques are available.  The advent of methods much more accurate and precise than those Hargrave had at his disposal gives us a valuable opportunity to make sure we’re starting on a firm foundation before we venture out into questions that were unsolvable or even unimaginable to previous generations of scholars.  This research is an excellent example of how to do that well.

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Aftermath: Mesa Verde

Edge of the Cedars Great House, Utah

The Mesa Verde region, which is generally considered to correspond to southwestern Colorado and southeastern Utah, or alternatively to the northern portion of the San Juan River watershed, has been one of the most intensively studied parts of the prehistoric southwest.  This is due to a variety of factors over the decades, most importantly the early work of the Wetherills and the more recent work of the Crow Canyon Archaeological Center.  The seventh chapter of The Prehistoric Pueblo World, about this region, draws mainly on the work of the latter, which sponsored the conference from which the book originated.  The authors are Mark Varien, Bill Lipe, Michael Adler, Ian Thompson, and Bruce Bradley, all of whom have been associated with Crow Canyon in various ways and to various degrees over the years.

This chapter takes a somewhat broader perspective than that taken by many of the others in the volume.  In addition to the rather large geographical area covered, the authors look at the evolution of settlement patterns over a much longer time period than the “Pueblo III” or “Post-Chaco” period, roughly AD 1150 to 1350, that is the main focus of all of the chapters.  This long view functions mainly as context for the discussion of Pueblo III developments, to be sure, but that’s important context to have in a region with such a long and complicated history of occupation.

Great Kiva at Lowry Pueblo, Colorado

The main issues of importance during the Pueblo III period in the Mesa Verde area are aggregation and abandonment.  As the authors of this chapter observe, neither is an entirely new development; aggregation into villages, some of which were quite large, was a notable feature of the Pueblo I period here, and those villages also seem to have been abandoned rather abruptly around the beginning of the Pueblo II period.  It’s not clear exactly what happened, but the whole region apparently underwent a rather severe decline in population at this time.  Of the various explanations offered for this, the authors of this chapter prefer the scenario in which the inhabitants of the aggregated villages moved south to the area of Chaco Canyon, where they were instrumental in the rise of the Chaco Phenomenon at around the same time.  This would certainly explain both the sudden population growth at Chaco in the early Pueblo II period and the many parallels between the nature of that growth and the earlier development of the northern villages.

In any case, however the rise and fall of the Pueblo I villages is interpreted, it’s quite clear that it happened, which shows that the aggregation and later abandonment of the whole region during Pueblo III was novel only in scale.  The authors of this chapter see the key to understanding aggregation in community structure, and particularly in the persistence of communities over time.  They present considerable evidence that the Pueblo II period in the Mesa Verde region was a time of dispersed settlement that was nonetheless characterized by organization into defined communities, some (but not all) of which construction Chaco-style great houses in the late eleventh century, rather late in the Chacoan era.  Whether they had great houses or not, these communities consisted of loose clusters of small houses or unit pueblos.

Dominguez Pueblo, a Small House Site in Colorado

In the early Pueblo III period, after the decline of the Chacoan system (whatever it was), these communities began to aggregate, at first just by bringing the dispersed small houses closer together.  Later, communities aggregated even more, often into compact, walled compounds surrounding springs or canyon heads.  This resulted in the famous cliff dwellings of Mesa Verde and other locations, along with the towers of Hovenweep and other sites that are generally taken as typical of the Mesa Verdean tradition.  These impressive, large sites, however, were occupied quite briefly, generally being constructed in the early or mid-thirteenth century and abandoned by 1300.

Hovenweep Castle, Utah

This process of increasing aggregation culminating in sudden abandonment is seen in other regions, but it is most pronounced here in the north.  Various explanations have been offered for it, often focusing on the clear environmental changes taking place in the 1200s that may have caused problems for settled communities dependent on runoff agriculture.  These include the “Great Drought” of AD 1276 through 1299, along with a possible shortening of the growing season due to the beginning of the Little Ice Age in the mid-1200s and increased variability in rainfall from year to year.  Any or all of these factors may have impacted the established communities in the Mesa Verde area.

However, as the authors note, these environmental problems were not actually enough to entirely explain the process of aggregation and abandonment.  Aggregation in particular is difficult to explain by deteriorating environmental conditions, given that it involves more intensive use of the increasingly limited resources in a given location, but even the regional abandonment was clearly not due entirely to the changes.  Studies of the carrying capacity of the Mesa Verde region have shown that on a regional level the prehistoric population couldn’t have come close to maxing out the available resources.  This region was and is very fertile and, unlike many other parts of the southwest, is a primarily agricultural area even today.  Indeed, as the authors point out, a dry year at Mesa Verde is still wetter than a wet year at Chaco or Hopi.

Westwater Cliff Dwelling, Utah

This is not to say that environmental factors are entirely beside the point here.  Part of the “in situ” model of aggregation that the authors posit involves substantial traditions of use-rights to particular lands, with the community serving in part as the mechanism for determining the extent of those rights.  The upshot of this in a time of deteriorating climatic conditions would be to artificially limit the amount of productive land (whether for farming or for hunting and gathering) available to a given household or community at a given time.  The overall result could very well be to make the increasingly large and immobile communities that developed as population increased overly dependent on the resources in a small area and unable to adapt to a series of bad years.  While it would be theoretically possible for such unlucky people to move to a different part of the region that was doing better, in practice they may not have had the social right to do so if the land “belonged” to someone else.  As a result, local-level environmental problems could end up having regionwide effects, culminating in regionwide abandonment.

As this scenario shows, given the facts at hand even a primarily environmental explanation for abandonment has to take into account social factors such as land-use histories.  Another possible social factor, which the authors of this chapter mention but don’t fully explore, is warfare, which could of course ultimately be driven by environmental changes either locally or more broadly.  As Steven LeBlanc has argued, the process of aggregation seen in many parts of the Puebloan world, including Mesa Verde, in the Pueblo III period is strongly suggestive of defensive considerations becoming paramount in the minds of the people building the settlements, and the increasingly fortress-like layout of the Mesa Verdean communities toward the end is particularly notable.  There is even a certain amount of direct evidence for warfare in the form of burned communities and human remains showing signs of violent death.  While the authors of this chapter certainly don’t ignore warfare entirely as a possible cause of the patterns they describe, they don’t give it the kind of centrality that LeBlanc does either.  Given the weakness of other explanations, however, I think the possibility of both aggregation and abandonment being primarily warfare-driven deserves serious consideration.

There’s a lot more in this chapter than I have mentioned in this post, and it’s definitely one of the most useful and accessible in the book.  One of the main purposes of the book and the conference at Crow Canyon whence it arose was to collect data in an accessible place for future research, and this chapter is a good example of a successful effort to do just that.

T-Shaped Doorways at Escalante Pueblo, a Great House in Colorado

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