ARCHAEOLOGY SOUTHWEST CONTINUE ON TO THE NEXT PAGE FOR YOUR magazineFREE PDF (formerly the Center for Desert Archaeology) is a private 501 (c) (3) nonprofit organization that explores and protects the places of our past across the American Southwest and Mexican Northwest. We have developed an integrated, conservation- based approach known as Preservation Archaeology. Although Preservation Archaeology begins with the active protection of archaeological sites, it doesn’t end there. We utilize holistic, low-impact investigation methods in order to pursue big-picture questions about what life was like long ago. As a part of our mission to help foster advocacy and appreciation for the special places of our past, we share our discoveries with the public. This free back issue of Archaeology Southwest Magazine is one of many ways we connect people with the Southwest’s rich past. Enjoy! Not yet a member? Join today! Membership to Archaeology Southwest includes: » A Subscription to our esteemed, quarterly Archaeology Southwest Magazine » Updates from This Month at Archaeology Southwest, our monthly e-newsletter » 25% off purchases of in-print, in-stock publications through our bookstore » Discounted registration fees for Hands-On Archaeology classes and workshops » Free pdf downloads of Archaeology Southwest Magazine, including our current and most recent issues » Access to our on-site research library » Invitations to our annual members’ meeting, as well as other special events and lectures Join us at archaeologysouthwest.org/how-to-help In the meantime, stay informed at our regularly updated Facebook page! 300 N Ash Alley, Tucson AZ, 85701 • (520) 882-6946 • [email protected] • www.archaeologysouthwest.org ™ Archaeology Southwest Volume 22, Number 4 Center for Desert Archaeology Fall 2008 Immigrants and Population Collapse in the Southern Southwest Jeffery J. Clark, Center for Desert Archaeology Patrick D. Lyons, Arizona State Museum and Center for Desert Archaeology J. Brett Hill, Hendrix College and Center for Desert Archaeology Anna A. Neuzil, EcoPlan Associates, Inc. William H. Doelle, Center for Desert Archaeology Carlo Gentile HAT HAPPENED TO THE HOHOKAM? is a question that has long intrigued and vexed South- Wwestern archaeologists. Recent research by archaeologists from the Center for Desert Archaeology has rephrased this question. We are now asking “How did more than 40,000 people vanish from the archaeological record of southern Arizona nearly a century before the arrival of the Span- iards?” Estimating past population using archaeological in- formation is difficult. However, only by using rough popu- lation estimates can we put our rephrased re- search question into perspective. The loss of Rene Muñoz 40,000 people repre- sents a more than sev- killed represented only two percent of the enty-five percent de- United States population in 1860. cline in population, a These two examples involved population staggering amount. loss and extreme social disruption that oc- In comparison, the curred over time frames of five years or less. Black Death, one of the Our research indicates that population de- deadliest pandemics in cline in the Southwest involved a much history, killed at least longer time frame. thirty-three percent of In 2003, the Center received a National Europeans between Science Foundation (NSF) grant that al- A.D. 1347 and 1350. lowed us to pursue new research to address And although the Civil this dramatic demographic decline. This is- War accounted for Contrasts in architecture: The Casa Grande, a four-story sue of Archaeology Southwest outlines the more American deaths adobe structure in use from 1350 to 1450, was part of a background and the results of this research. large settlement with many adobe compounds (courtesy than all other wars from Library of Congress). In the late 1600s, the Sobaipuri The contrast in population between 1400 the American Revolu- Indians, who spoke the O’odham (Piman) language, lived and 1700 is tion through the Viet- in small oval structures that left faint traces in the ar- highlight- Archaeology Southwest nam War combined, chaeological record. The rocks were used to anchor the ed in docu- is a Quarterly Publication of the bent-pole frames of these houses. the number of people ments and Center for Desert Archaeology Population distribution across the Southwest in fifty-year intervals from 1200 to 1500. Density intervals per 100 km2: 10, 50, 100, 250, 500. in the archaeological record. In 1697, Captain Juan Mateo for a decline of this magnitude has been debated for more Manje accompanied Father Eusebio Francisco Kino on than fifty years, with migration, floods, drought, disease, an exploratory journey along the length of the San Pedro overpopulation, and warfare offered as possibilities. River and then westward along the Gila. Manje wrote in Understanding this phenomenon requires both de- his journal about the impressively thick adobe walls of the tailed studies of individual valleys and a broad geographic Casa Grande Ruin. He described the large irrigation canal and temporal perspective. With respect to the latter, the that not only brought water to the A. Devitt Mathew Center, in collaboration with the area, but also, in Manje’s assess- Museum of Northern Arizona ment, could have served as a de- and Western Mapping, Inc., de- fensive moat. He compared the nu- veloped the Coalescent Commu- merous decaying casas grandes to nities Database. This ambitious European castles. In contrast, when project created a Geographic In- he and Kino arrived at a nearby formation System (GIS) database O’odham village several miles to that contains all known sites in the west, Manje made no mention the Southwest having more than of irrigation canals and stated that twelve rooms and dating from the houses were “built with poles 1200 to 1700. These data have and covered with mats.” been used to estimate how many The archaeological record in Jannelle Weakly rooms were occupied at each site southern Arizona contains very few in each fifty-year interval during securely identified sites that date this 500-year period. These room between 1450 and 1650. However, counts are the basis for site-level several indigenous sites have been population estimates and regional excavated that date to the late demographic reconstructions 1600s, at approximately the time of across the Southwest (see popu- Manje’s travels. The photographs lation trends figure, above and on page 1 show the contrast be- page 3). tween the structures built in late Several trends bear directly on Hohokam times and those built in this population collapse. First, be- the 1690s. ginning in the late 1200s, there Most archaeologists agree that was a general southward move- these differences point to a drastic ment of people from the Four population decline in the indig- Contrasts in ceramics: Salado polychrome vessels were Corners area. Groups that were enous communities in southern widely made and traded between 1300 and 1450. In dependent on rainfall farming contrast, only a few plain wares were being made and Arizona prior to arrival of the Span- used by the Sobaipuri in the late 1600s (both photos moved into river valleys where ir- iards. Nevertheless, an explanation courtesy Arizona State Museum). rigation agriculture could be Page 2 Archaeology Southwest Volume 22, Number 4 practiced. The depopulation of southwestern Colorado Using the broad trends identified by the Coalescent coincided with a substantial population increase in the Communities Database, the Center conducted detailed re- northern Rio Grande. Small migrations of Ancestral Pue- search in five study areas that represent the range of envi- bloan groups from northeastern Arizona can be traced to ronmental and social diversity in late pre-contact south- river valleys in southern Arizona. At about the same time, ern Arizona. The goals of our research were to understand people who had been living in smaller settlements aggre- the role that Ancestral Puebloan migration played in coa- gated into fewer, but larger, settlements. We believe that lescence and to evaluate possible connections between coa- migration and aggregation were related parts of a single lescence and the subsequent population collapse. process we call coalescence. In addition to the lower San Pedro Valley, study areas Second, the time around 1300 was the period of maxi- in the NSF project included the lower Salt River Valley, mum population in the Southwest, with the greatest con- Perry Mesa area, Tonto Basin, and the Safford Basin. Our centration by far in the Phoenix Basin. focus was on re-examining existing museum collections, Finally, substantial population loss is indicated across primarily those from recent cultural resource management southern Arizona by 1400, several generations after coa- projects. This was augmented by small-scale fieldwork. lescence occurred. This loss cannot be attributed to a single This issue of Archaeology Southwest presents prelimi- catastrophe, but instead, took place over at least several nary results of this research project. We begin with an over- generations and perhaps as long as 150 years. At the same view of migration. Then, the methods and artifact analy- time, the mountainous zones in central Arizona were de- ses used to achieve our research goals are discussed, and populated, creating a demographic and perhaps commu- we present a summary of past research and project results nication “fault zone” between the inhabitants of the for each of our five study areas. A final section identifies Sonoran Desert and the Colorado Plateau. No major popu- common themes and broad patterns in population coales- lation centers survived in southern Arizona after 1450. cence and its subsequent decline across southern Arizona. Overview of Migration O PUT OUR RESEARCH in context, it is helpful 1,500 and 3,000 immigrants is believed to have been to first consider the scale and sources of population present. The small number of immigrants makes the ulti- Tmovement, or migration. We believe that Ancestral Pue- mate magnitude of their impact particularly interesting.