Culture and Ecology of Chaco Canyon and the San Juan Basin

128 Chaco Project Synthesisfor irrigation systems were located (Gwinn Vivian1983b). The presence of canals, mostly on the northside, and the long-term changes that their presencewould imply, would be one clue to help explaindifferences between settlements in the canyon.Differences in site size on the two sides of thecanyon and initial acceptance of Kidder' s (1924) PecosClassification had led to the proposition that smallsites were constructed and used earlier than largepueblos. Excavations at Bc 50 and Bc 51 (Hawley1937b; Kluckhohn 1939a) negated that concept; thesesmall sites were contemporaneous, in part, withChetro Ket!. Yet site size and evidence of materialculture differed. The different architectural and potterystyles uncovered at Kin Kletso (Gordon Vivianand Mathews 1965) supported the possibility of threedifferent groups; this McElmo style could represent alate migration.The presence of copper bells, macaws, and otherimports, plus similar architecture at several large sitesin the San Juan Basin, were recognized as evidence forlong-distance trade. Based on a comparison of architecturalfeatures, the question of Mesoamerican influencewas raised again (Ferdon 1955). Researchersworking in northern and western Mexico were pursuingthese lines of investigation (DiPeso 1968a,1968b, 1974; J. Kelley and Kelley 1975). Theirmodels proposed that foreigners would have beenresponsible for teaching local populations about craftsand masonry techniques, and that the florescence ofChaco could be correlated with events farther south.Thus, a regional perspective would be needed to integratedata from sites resembling Chaco (e.g., Aztec[Morris 1928], Lowry [Paul Sidney Martin 1936], andthe Village of the Great Kivas [Roberts 1932]), and toevaluate the concept of foreign influence.If the Pueblo social organization evident inChaco was indigenous and similar to that of historicpeople, possible reasons for abandonment included 1)accumulation of black alkali soils that became imperrnerabledue to irrigation (Judd 1954:60); 2)progressive up-canyon arroyo-cutting (Bryan 1954);and 3) elimination of perennial cover through farming,which led to soil erosion and abandonment of fields.Because there were no tree-ring dates for the periodfrom A.D. 1126 to 1300, Gordon Vivian andMathews (1965) thought the Classic period was muchlike today, but that between A.D. 1276 and 1299conditions were twice as dryas at present.In summary, the Classic period provided evidencefor contemporaneous occupation of small andlarge sites, with two different architectural stylesdescribed for the latter. Egalitarian social organization,migration of people, and long-distanceexchange were possible explanations for thedifferences between "towns" and "villages." Ethnographicanalogy provided models to explain Chaco aspart of a long-standing Puebloan system, or the resultofpochteca traders from Mexico. Either organizationcould have been responsible for the unusual developmentsrecorded in Chaco Canyon.With the wealth of new data resulting from theChaco Project, it is now possible to divide Bannister's(1965) "Classic· period into finer segments: TheEarly, Classic, and Late Bonito phases (Appendix B:Table B.1). This chapter will focus on survey andexcavation data that indicate evidence for change atboth large and small sites during the period from A.D.850 to 1150 and the propositions put forth to accountfor that change. How more specific chronologicaldivisions evolved is seen in the survey and excavationdata presented below.Survey ResultsJudge (1972) defined Pueblo II small sites asthose with surface rooms, a kiva depression, andceramics that were comprised predominantly of RedMesa and Gallup black-an-white ceramic wares, witha high percentage of corrugated utility ware. How toassign small sites to Pueblo III was less clear. Thecontemporaneity of Bc 50 with the great houses(Kluckhohn 1939a:156-157) and Gordon Vivian's(Vivian and Mathews 1965:29) exclusion of coredmasonry, internal kivas, and McElmo Black-on-whitefrom Pueblo II prompted Judge to base distinctions onceramic types. Mancos Black-on-white, McElmoBlack-on-white, Tusayan Black-on-white, and WingateBlack-on-red were considered evidence for a PuebloIII assignment. As a result, 59 sites in the transectsurvey were classified as Pueblo II, and 58 as PuebloIII.Pueblo II small sites lacked any general associationswith environmental attributes (Judge 1972).