In 2009, environmental journalist Robert Moor undertook a thru-hike of the Appalachian Trail. That hike sparked an interest in the origins of trails—how they are formed, the functions they serve, and the meanings we ascribe to them. Drawing from the wisdom of cultures from ancient China to the Beat poets, On Trails combines science, wanderlust, and philosophy to explore this rich tradition.

Moor starts by tracing the oldest known paths, 565 million-year-old fossils trails of Ediacarans in Newfoundland’s Mistaken Point. He describes how insects optimize paths to food sources, exhibiting a form of collective intelligence that has been adapted to improve fiber-optic networks and shipping routes. Migration routes of mammals provide a backdrop for discussion of how early societies formed and interacted along game routes. Moor explores Native American footpaths, the ways they shaped US history, and the forced exile of the Trail of Tears. He discusses how the creation of the Appalachian Trail coincided with a new appreciation for the wilderness, as early 20th century America became increasingly urbanized. Moor reflects on the ways technology and modern transport connect yet separate us as he hikes through Morocco, helping to find an optimal route for the extension of the International Appalachian Trail.

Reflecting on the book, I was reminded of the other trails followed by medical professionals, namely clinical practice guidelines and treatment protocols. As with other pathways, it is important to consider where the path leads, who built the protocol, and how it is maintained. Is the protocol meant to set a minimum standard of care, or does it describe a higher level that centers should strive to reach? Is the guideline a product of experts with little clinical experience outside of academic centers, or can it be applied in a variety of settings with different resource limitations? Is the protocol efficient and cost-effective, or are there detours through conflict of interest and influence by Big Pharma? How quickly is new evidence incorporated and discredited information removed? Moor’s description of trails “ushering us through the world while still preserving our sense of agency and independence” is no less apt in the clinical setting.

Trails take us into the wilderness, foster connections between people, and lead us home again. It is telling that many cultural traditions use the metaphor of a path to describe the right way of living. Hikers and wilderness enthusiasts will enjoy meandering along with Moor, and perhaps find inspiration for their next adventure.