Culture and Ecology of Chaco Canyon and the San Juan Basin

124 Chaco Project Synthesisobligations could not be paid through goods orservices (e.g., ceremonial duties, labor, or assistancein warfare or defense), reciprocity and mutual aid thatexisted among kin groups would have been strained.A pattern ofleaders and followers emerged. Sebastiansuggested that throughout the Anasazi region there isevidence of such differentiation. Although she did notsee leaders achieving permanent roles, they couldconvert their success into ascribed status roles. Thetwo distinct uses of pit structures (as domestic quartersand as ritual settings) may indicate that someindividuals or groups began to build "a power base ofritual knowledge and access to the supernatural"(Sebastian 1992b: 104).Although data from the Chaco Project did notdirectly tie the Archaic settlements to those ofBasketmaker III, Stuart (2000) recently elaborated onhow choices made during one period affect lateroutcomes. He suggested that a period of unstableprecipitation from 500 B.C. to A.D. 1 would have ledto some experimentation with cultigens, which overtime meant a larger investment in time to secure food.The presence oflarge com cobs and new com types inarchaeological sites dated to this period, plus theexistence of large and more permanent camps withsome storage facilities, indicate that some people wereshifting toward a slightly more sedentary life styledependent on a greater labor input.With the rise in precipitation and water tablesjust prior to A.D. 1, the ground water in intermittentstream beds would have been sufficient to supportsmall-scale agriculture. A dependable food source inone place would be advantageous to people living ina patchy environment. As a result, there would besome areas where farming became more intense. Thefew scattered pithouses and greater storage in suchsettings attest to such beginnings. Those families whochose this more labor-intensive food productionstrategy would be able to produce more children. Inthe long run, they would overcome the traditionalhunters and gatherers.Stuart characterized the Basketmaker period asone of experimentation. During the early Basketmakerperiod (A.D. 1 to 400), settlements with pithouseswould be established in upland elevationsoverlooking lower ground near streams and intermittentwashes that allowed better farming. Contemporarysites in dune areas would have ramadas butnot pithouses; these would be hunter-gatherer seedprocessingsites. He interpreted these two sets of sitesas 1) fall and winter settlements with pithouses; and 2)spring and summer foraging camps at lowerelevations. A major revolution in cooking is indicatedby the appearance of pottery around A.D. 300 to 400.Between A.D. 400 and 750, or Late Basketmaker,pithouse settlements increased in size. Larger settlementsare found in uplands, but as populationincreased by the A.D. 600s and 700s, hamletsappeared in lower and more open basins such as ChacoCanyon. An increase in population growth by theA.D. 800s locked the popUlation into a pattern.During the Pueblo I period, Stuart proposed amore conservative approach. The decrease in precipitationduring the late A.D. 700s and its more erraticappearance made uplands more attractive. A shortergrowing season would make agriculture moreunpredictable and increase trade relationships betweencommunities that would share risks. Experimentswith new types of com and learning the advantages offarming in better watered areas would contrast withmoving, foraging, and trading. Thus, there would bean enhancement of trade and social connections. As aresult of what he terms "mixed signals," Stuart sawthe period between A.D. 760 and 860 as one needingnew solutions.But at A. D. 800 most of the lowlands weresimply not yet the place to be. LowlandBasketmaker sites similar to Shabik'escheeVillage in Chaco Canyon were abandonedaltogether, and no Pueblo I sites were builton top. Many of the lower-elevationBasketmaker sites are believed to havebeen used only intermittently orseasonally, when intervals of cooler,wetter climate favored temporary gardeningthere. Three notable exceptions liein Chaco Canyon itself, where Pueblo J­style settlements built just after 800 areconsidered the oldest core units at theeventual "great-house" sites of PuebloBonito, Penasco Blanco, and Una Vida.Each had an unusual number of multistoryrear storage rooms behind the residencesand pithouses. Why should Chaco Canyonhave been an exception? And why, apart