Culture and Ecology of Chaco Canyon and the San Juan Basin

Basketmaker III to Pueblo I 99In summary, at the start of the Chaco Project,there were several issues that deserved attention.Among them were the difficulty in estimating thenumber of pit structures buried under several feet ofalluvium along the main Chaco Wash or under latersite components, in assigning dates to components, ininterpreting the variability in architectural features forcontemporary sites, the settlement pattern, and thepossibility that more than one group lived within thearea. It would be difficult to understand the transitionsfrom horticulture to agriculture and from pitstructures to above-ground houses without better datedexcavations.This chapter will focus on information gatheredduring surveys and excavations in order to addressthese issues. The final report on Basketmaker III­Pueblo I excavations (windes 2006a) will providegreater detail. Here, I have relied heavily onMcKenna's (1986) synopsis of small-site excavationsand Truell's (1986) synthesis of small-site architecture,which provide careful analyses of changes inpit structures and above-ground structures throughtime. Their information is combined with artifactanalyses and other studies to provide a picture of thefoundations for later developments in Chaco Canyonand the San Juan Basin.Chaco Project StudiesThe Chaco Prospectus (NPS 1969) recommendedthat ceramic and architectural sequences be reevaluatedand populations be estimated in order tobetter understand the shift of Basketmaker sites typicalof the southern half of the San Juan Basin into theChaco area and the shift from mesa top locations tovalley bottom locations. Changes in the environmentthat related to the discovery of pithouses beneath thepresent surface along the Chaco Wash neededclarification.Survey DataJudge's transect survey crew identified 43Basketmaker III sites based on the presence ofdepressions, indicating pithouses, and a dominance ofLino Gray pottery. An absence of surface structureswas a major factor in distinguishing these sites fromlater Pueblo I sites (Judge 1972:31-32). Although theBasketmaker III sites were found at similar mean siteelevations as earlier Preceramic sites, their location onMenafee Shale 66 percent of the time and on sandstone24 percent of the time was exactly opposite from theearlier site distributions with regard to geologicalsubstrate. The mesa and canyon edge locations ofmany of the open-air Preceramic sites would havebeen unsuitable for the construction of pithouses.Judge also attributed this difference to an associationof Basket maker III sites with a low average distance tothe nearest stream, especially when compared withsites assigned to different periods. Basketmaker IIIsites were generally found on hills, ridges, or activedunes in upland areas south of Chacra Mesa, as wellas on the elevated Menafee Shale outcroppings foundat mesa bases in close association with tributariesrather than major streams.Hayes's (1981) inventory survey assigned datesfor the Basketmaker III period from A.D. 400 or 500to A.D. 725 or 750. Subcircular subterranean pithouseswith antechambers or large ventilator shaftshad oval or bean-shaped cists located behind them.Characteristic artifacts included two major ceramictypes (Lino Gray and La Plata Black-on-white);imported ceramics from the Mogollon region (darkredwith black smudged interiors); bows and arrowsinstead of atlatls; and deep trough metates.Usingthese criteria, the survey crews identified a total of188 Basketmaker III sites located on mesas (n=60),on plains (n = 40), and in bottomlands (n = 88) (Hayes1981:Figure 13).Because 15 Basketmaker III sites were found incutbanks of canyon bottom arroyos, Hayes (1981:24)was concerned about site visibility for these pitstructures. Windblown sand quickly covers pitstructures on mesa tops (e.g., Roberts's [1929] needto trench to uncover pithouses at Shabik'eshcheeVillage), and exposures in arroyo cuts indicatedconsiderable aggradation of the Chaco Wash overtime. Hayes estimated a rate of deposition of about3.9 m (13 ft) in 500 years, and suspected that 150 sitesmay have been buried in the floodplain and notrecorded. If Hayes's estimate is correct, approximatelytwo-thirds of the Basketmaker III sites wouldhave been located in the bottomlands, closer tointermittent streams.Two great kivas were recorded, one atShabik'eshchee Village and the other at 29SJ423 on