This publication serves as a diagnostic reference for identifying common pathogens and insect infestations affecting forest ecosystems in Idaho and Montana. The authors, affiliated with the USDA Forest Service, synthesize field observations and biological data to provide forest managers and landowners with a practical framework for identifying tree health issues.

Experts recognize this publication as a standard field reference for regional forest health monitoring. Readers frequently note the practical utility of the visual aids for on-site identification in remote forest environments.