Students from North and South America, Europe, Asia, and Africa are meeting at the University of Arizona Laboratory of Tree-Ring Research (LTRR) for a 3-week summer pre-session training course. Lead instructors are Don Falk (SNRE/LTRR), Margaret Evans (EEB/LTRR), Ann Lynch (US Forest Service/LTRR) for dendroecology, and Ron Towner (Anthropology/LTRR) for dendroarchaeology. Dendrochronology is the study of natural and human processes that are recorded in the tree-ring record. This record is retained over time due to the remarkable preservation qualities of wood, and across the wide geographical distribution of trees. Through the science of dendrochronology, a broad range of ecological, climatic, geological, and cultural variables can be reconstructed and analyzed with high spatial and temporal resolution. The dendroecology group is focusing on forest responses to climate variation, fire, and insect outbreaks in the Sky Islands, while the dendroarchaeology course is examining questions in Southwestern human history.