With 65 species of trees and shrubs, Black Rock Forest serves as a premier outdoor classroom for the study of dendrology. Students learn to navigate the forest’s diversity by using a dichotomous key, a step-by-step tool that uses leaf anatomy, bark texture, and branching patterns to identify 25 of the most common woody species. While younger learners begin by sorting leaves to discover distinguishing attributes, older students can test their skills on a numbered tree course, where they apply the key to real-world specimens. This curriculum is adaptable for all seasons; after the leaves fall, the challenge increases as students learn to “key out” species using only bark, twig, and bud characteristics. To support these lessons, we provide comprehensive worksheets, identification guides, and more to help students bring their findings back to the classroom.