The study of tree response to environmental conditions is called dendroecology. This discipline can offer key advice to forest practitioners regarding when landslides or flooding have occurred in the past. When trees are tilted, buried, or scarred by events, or established on sediment following an event, a record is left in the tree rings. This guidebook provides forest practitioners with information and straightforward techniques for interpreting those records. The additional time and expense incurred is of minor importance compared to the information generated and the degree of confidence that can be placed in the identification of geomorphic and hydrologic hazards influencing a site.