Nicholas Kessler is a Post-Doctoral Research Associate in the Physics Department and the Laboratory of Tree-Ring Research at the university of Arizona, earning his PhD at the University of Arizona School of Anthropology. Dr. Kessler’s research has included dendroarchaeological projects in Arizona, New Mexico, Kansas, and Illinois. He has also published studies on soil chemistry and ancient agriculture in the Northern New Mexico. His primary research for the last two years has been on redating the Hawley-Bell wood collection in collaboration with the Center for Archaeological Research at Southern Illinois University. This work has now expanded to include other regional archaeological sites in collaboration with the Illinois Archaeological Survey, University of Illinois at Champaign-Urbana. This work involves ring-width dendrochronology, ¹⁴C wiggle-matching, and Strontium isotope wood sourcing. Today’s presentation summarizes recently published and unpublished results of tree-ring studies at the Kincaid and Mitchell sites, ancient ceremonial and political centers in southern Illinois occupied between ca. 1100–1450 AD.