Refortifying Cahokia More Efficient Palisade Construction through Redesigned Bastions Abstract Anthony Michal Krus Glenn A. Black Laboratory of Archaeology, 423 N. Fess Avenue, Bloomington, IN 47405 (amkrus@indiana.edu) Department of Anthropology, Indiana University Bloomington, IN 47405 The number of posts in the initial and subsequent construction of Cahokia's Central Palisade was recalculated using new measurements of the postholes, bastions, and changes in the perimeter of the pali- sade that resulted from its multiple reconstructions. Application of this recalculation indicates that each construction of the palisade may have used fewer posts than previously estimated. These data also sug- gest that both the number of posts needed for construction and the number of person-hours needed for construction decreased between 22.5 to 27.5 percent from its second to its final construction episodes, and that the Central Palisade always used wood more effidently each time it was reconstructed. This may reflect a consdous attempt by Cahokians to conserve wood resources through changing the Central Palisade's architecture. Located approximately 13 km east of modern day St. Louis, Missouri, Ca- hokia Mounds is one of the largest pre-Columbia settlement north of the Texas-Mexican border (Iseminger 1996:30). It occupies an area of at least 12 km 2 and includes 120 earthen pyramids and large wooden monuments (Dalan eta!. 2003:87-88; Iseminger 1996:30). The most intensive occupa- tion of Cahokia occurred during the Middle Mississippian period, between the Lohmann and Moorehead phases (A.D. 1050 and A.D. 1350) (Fortier eta!. 2006:fi.gure 6; Milner 1998; Pauketat 2007:146, 149, 162). One of the more conspicuous features at Cahokia was the Central Palisade. Construc- tion of the Central Palisade began in ca . A.D . 1135, and it was reconstructed three times in the following 80-200 years (Holley eta!. 1990:62; Iseminger 1990:36). A total of 15,000 to 20,000 wooden posts were believed to have been used during these construction episodes (Iseminger 1990; Pfeiffer 1974). An accurate estimate of the numbers of posts is important because they are the primary variables used to determine the number of person-hours necessary Midc onrinental Journal of Archaeol ogy, Vol. 36, No.2 ( Fall 2011 ), pp. 227·244. Copyright o 2011 Midwest Archaeological Conference, In c. All ri ghts rese rved. 227