In Search of Chaco New Approaches to an Archaeological Enigma Chaco’sone Golden Century W. James Judge In the hundred years between 1030 and 1130 CE, that commonly come to mind when people visit residents of the central San Juan Basin of north- Chaco Canyon and examine its archaeology. western New Mexico expended almost unbelievable human energy to create a cultural landscape of epic Why Did Complexity Emerge in Chaco proportions, a truly enduring architectural master- Canyon and Not Elsewhere? piece. They constructed massive buildings, great An unusual configuration of environmental features kivas, formal stairways up cliffs and mesas, a system made Chaco Canyon a rarity in the San Juan Basin. of roads, and complex irrigation systems. Then, Reconstructions of the ancient climate, based on shortly after 1130, this unprecedented burst of analyses of tree-ring patterns, fossil pollen, and the human endeavor faded away almost as quickly as contents of packrat middens, indicate that the central it had begun. These hundred years were Chaco San Juan Basin has been dry—with an average of 8.5 Canyon’s golden century, a period virtually inches of annual precipitation—for several thousand unmatched elsewhere in the pre-Columbian years. Yet within the basin, Chaco Canyon is a geo- Southwest. logical anomaly. It runs generally east-west, exposing Chaco Canyon is a desolate place by modern a set of cliffs in the bedrock sandstone several hun- standards, seemingly devoid of most of the basic dred feet high. The cliffs are especially pronounced resources necessary to build the complex society that on the north side of the canyon, where they are emerged there—which makes that accomplishment capped with an expanse of bare slickrock. even more perplexing. Equally astounding is the A series of side canyons, or rincones (“rincons” rapidity with which the events took place. In 1030, in English usage), channel runoff to the main canyon only three structures were prominent on the Chaco floor. The bottoms of the rincons and the canyon Canyon landscape. Seventy years later, the canyon itself are level and thus were suitable for irrigation was home to a dozen massive buildings (“great hous- farming by the Chacoan people. es”), each with hundreds of rooms. It boasted two Another factor is that the canyon lies just west separate great kivas, an extensive canal irrigation of Chacra Mesa, the highest mesa in the central San system, and a network of formal roads, ramps, and Juan Basin and an area rich in plants and animals that stairways connecting the great houses. Further, people could efficiently exploit. At its western edge,the Chaco Canyon served as a ceremonial center linking canyon joins Escavada Wash, where the water table possibly two hundred outlying sites dispersed surfaces to provide even greater agricultural potential. throughout the San Juan Basin. Concentrated at the center of this near desert, then, Archaeologists and visitors alike crave an Chaco Canyon’s unique diversity of geological and explanation of the Chaco phenomenon. One way biological resources made it a relative oasis in which to attempt to explain it is to ask a series of questions a complex society had an opportunity to emerge. COPYRIGHTED MATERIAL Figure 1.2. Chaco Canyon from the air, looking northwest, with Fajada Butte in the foreground. Why Did Chaco Flourish in the Eleventh canyon sufficiently to increase the agricultural Century and Not Earlier? potential there even more. In the eleventh century, an increase in population and The years from 990 to 1030 CE were ones of a combination of environmental factors converged to generally favorable precipitation. In the late 900s, create, for the first time, the conditions necessary for taking advantage of the relatively bountiful environ- Chaco Canyon’s florescence. First, population had ment and perhaps in order to store surplus farm pro- been gradually increasing in the central San Juan duce, Chaco’s inhabitants erected the canyon’s first Basin since the advent of agriculture and village life in three great houses: Peñasco Blanco, Pueblo Bonito, the sixth and seventh centuries. In the 900s CE, it was and Una Vida. In addition, it is possible that canyon augmented by immigrants from the San Juan River residents developed irrigation canals and gridded region, over one hundred miles to the north. By the fields in the early 1000s to capture slickrock runoff early 1000s, many large Pueblo settlements were dis- during intense summer storms. Of the twenty-eight persed throughout the basin, providing a population rincons adjoining the canyon, seventeen are known threshold for the emergence of complexity. to have had irrigation systems, making Chaco one Second, the recent discovery of a former natural of the few places in North America in which people sand-dune dam just above the confluence of the constructed extensive canal irrigation networks based Chaco and Escavada Washes suggests that sufficient solely on precipitation runoff. Thus, a combination water may have been impounded to create a marsh- of early-eleventh-century environmental factors and like wetland at the west end of Chaco Canyon (see a general population increase set the stage for the chapter 2). Together with an aggrading streambed, emergence of the complex sociopolitical system that the dam would have raised the water table in the was to define Chaco’s florescence. 2 Chaco’s Golden Century COPYRIGHTED MATERIAL Figure 1.3. Chetro Ketl, with the great kiva in the foreground. What Happened in the Canyon to Create rounding areas. Sodalities are sociopolitical entities the Chaco Phenomenon? that draw their membership from kin-based organiza- Scholars have referred to the extraordinary develop- tions such as lineages and clans but are not them- ments that took place in Chaco Canyon as the selves based on kinship. As such, they cut across “Chaco phenomenon.” Archaeologists calculate that existing social units and bind together diverse ele- during the eleventh century, massive amounts of ments of a society. Perhaps a common belief system, human energy—more than four hundred thousand manifested in shared rituals, helped the Chacoans person hours—were invested in construction in the cope with their challenging environment and inspired canyon. The Chacoans built four new great houses— them to build ceremonial centers, just as other people Hungo Pavi, Chetro Ketl, Pueblo Alto, and Pueblo around the world have built temples, cathedrals, and del Arroyo—each according to a similar “D-shaped” mosques. It might also have served to offset potential architectural plan. They constructed two stand-alone conflict among diverse cultural groups in the San great kivas, now known as Casa Rinconada and Kin Juan Basin. The leaders of this society might have Nahasbas, as well as several great kivas inside the been priests who controlled the organization through plazas of existing structures. They engineered roads their knowledge of religious rituals. that connected the canyon great houses, and in some Other scholars think that one or more formal places they built dirt and masonry ramps and formal sociopolitical entities called chiefdoms evolved in staircases to ascend the cliffs. Chaco, with leadership based more on social rank or Chacoan researchers debate the motivating force status than on ritual knowledge. In such chiefdoms, behind this labor investment. Some have suggested the power base of the leaders, or chiefs, can be seen that a ritual “sodality” emerged to integrate the in the accumulation of material wealth. This wealth diverse groups living within the canyon and its sur- can be envied and challenged and leads to increased Chaco’s Golden Century 3 COPYRIGHTED MATERIAL competition both within and among chiefdoms. gists are now rethinking earlier interpretations in Archaeologists question this model of Chacoan com- which they viewed great houses as residences for plexity, noting that except at Pueblo Bonito, little large numbers of people. Previous population esti- evidence of such wealth has been uncovered in the mates of more than ten thousand for Chaco Canyon excavated Chacoan great houses. Further, a political are being reduced to fewer than two thousand. This system that fostered competition among aspiring revised view suggests that the great houses might not leaders would have been generally less capable of have been primarily residences. But if they were not, integrating the dispersed and diverse communities and if they did not house a large population, why of the San Juan Basin. Religious authority, on the were they built? other hand, encompasses an entire belief system and One clue might be found in the manner in which so is more inclusive and integrative. Virtually all great houses were designed and constructed over researchers recognize a strong ritual component to time. As Chaco Canyon was emerging as a ceremoni- Chacoan authority and view the Chacoans as having al center, perhaps the great houses were planned as formed a regional center with a compelling and inte- monumental architectural expressions of Chacoan grating body of ceremony at its core. ritual. For example, Chetro Ketl, the largest of the D-shaped structures in the canyon, with three stories Why Were the Chacoan Great Houses Built, and some five hundred rooms, was built in distinct and What Were They Used For? stages over an eighty- to ninety-year period in the The function of the Chacoan great houses has long eleventh century. Without written records, how did puzzled researchers. Of the hundreds of small sites its builders adhere to its original architectural design excavated by archaeologists in the Southwestern throughout decades of construction? Perhaps the United States, most are clearly residential. They con- foundation for the entire structure was laid at the tain fire pits, storage and sleeping areas, and places to outset as a kind of master plan to guide the genera- do household work. Chacoan great houses have few tions of workers who followed.