For various practical reasons, principally to do with the long, punishing winters of northern New England, there are only so many available months to hike the trail each year. If you start at the northern end, at Mount Katahdin in Maine, you must wait for the snows to clear in late May or June. If, on the other hand, you start in Georgia and head north, you must time it to finish before mid-October, when the snows blow back in. Most people hike from south to north with spring, ideally keeping one step ahead of the worst of the hot weather and the more irksome and infectious of insects. My intention was to start in the south in early March. I put aside six weeks for the first leg.

The precise length of the Appalachian Trail is a matter of interesting uncertainty. The U.S. National Park Service, which constantly distinguishes itself in a variety of ways, manages in a single leaflet to give the length of the trail as 2,155 miles and 2,200 miles. The officialAppalachian Trail Guides, a set of eleven books each dealing with a particular state or section, variously give the length as 2,144 miles, 2,147 miles, 2,159 miles, and “more than 2,150 miles.” The Appalachian Trail Conference, the governing body, in 1993 put the trail length at exactly 2,146.7 miles, then changed for a couple of years to a hesitantly vague “more than 2,150 miles,” but has recently returned to confident precision with a length of 2,160.2 miles. In 1993, three people rolled a measuring wheel along its entire length and came up with a distance of 2,164.9 miles. At about the same time, a careful measure based on a full set of U.S. Geological Survey maps put the distance at 2,118.3 miles.

What is certain is that it is a long way, and from either end it is not easy. The peaks of the Appalachian Trail are not particularly formidable as mountains go-the highest, Clingmans Dome in Tennessee, tops out at a little under 6,700 feet-but they are big enough and they go on and on. There are more than 350 peaks over 5,000 feet along the AT, and perhaps a thousand more in the vicinity. Altogether, it takes about five months, and five million steps, to walk the trail from end to end.