northern terminus. It had the air of a shrine. Groups of day hikers hung back from it, forming a respectful half-circle, while a handful of thru-hikers approached it, one by one, with looks of reverence and tamped expectation. Each hiker had a moment alone with the sign, posed for a photograph to commemorate the occasionâsome exuberant, some somberâand then moved on, allowing the next hiker to approach.
When my turn came, I walked up to the sign, laid my hands on it, and kissed its wind-scoured surface. The moment held a certain surreal quality; I already had imagined it a thousand times. My friends and I popped a bottle of cheap champagne, which we shook and sprayed in fanning arcs into the air. When we finally took a sip, thechampagne had already gone flat and warm. That was a rough analog for how it felt to finish the trail: buzzy and yet weirdly dull. After five months, it was over.
And yet, when I moved back to New York City, I found that I continued to look at the world with the eyes of a thru-hiker. After almost half a year spent in mountainous wilderness, the city seemed at once a marvel and a monstrosity. It was hard to imagine a space more thoroughly transformed by human hands. What struck me most, though, was its rigidity: straight lines, right angles, cement roads, concrete walls, steel beams, harsh rules regulated by force. Waste was rampant; everything broke. The trail had taught me that good designsâlike age-old tools and classic folktalesâare trail-wise : They fulfill a common need by balancing efficiency, flexibility, and durability. They streamline. They self-reinforce. They bend but do not break. So much of our built environment, by comparison, seemed terribly, perilously inelegant.
Meanwhile, everywhere I looked, I noticed new trails: a desire line winding through a tiny park beside the East River, a line of ants inching along my windowsill. I noticed how the shoes of passing commuters wore greasy lines into the concrete of the subway platform, how spots of blackened chewing gum and flattened cigarette butts marked the entrance to nightclubs. Reading omnivorously, I discovered trails running thick through works of literature, history, ecology, biology, psychology, and philosophy. Then I put the books down and walked some more, seeking out fellow travelersâtrail-walkers and trail-builders, hunters and herders, entomologists and ichnologists, geologists and geographers, historians and systems theoristsâin the hopes of gleaning some common truths from their diverse fields of expertise.
Somewhere along the way I realized that at the heart of my thinking lay a simple idea: A trail sleekens to its end. An explorer finds a worthwhile destination; then every walker who follows that trailmakes it a little better. Ant trails, game paths, ancient ways, modern hiking trailsâthey all continually adapt to the aims of their walkers. Hurried walkers make straighter paths and leisurely walkers make curvier ones, just as some societies seek to maximize profit, while others strive to maximize equality, or military might, or gross national happiness.
The path of a runner often diverges from that of a walker, because, though both may be headed to the same place, they do so with differing priorities. A New Zealand sheep farmer named William Herbert Guthrie-Smith once observed that horse trails in open country will gradually straighten out. However, he noticed that this only took place in areas where the horses were allowed to trot, canter, or gallop. At a slow walk, the horses gladly followed each turn of a sinuous trail, minimizing their work by bending with the contours of the topography. When they sped up, they began to cut the inside corners off the curves, straightening them. If the horses had been allowed to run âat racing speed,â Guthrie-Smith believed they would âin time rule out paths almost perfectly straight.â
The lesson to be found here is not just that the