A sizeable body of literature is available on the east-west pathways of the American continent, including the famous wagon train trails that helped to colonize the nation to the shores of the Pacific. Any study of these routes ranging from footpaths to early American highways is accompanied by an equally vibrant collection of popular literature. In the perception of the American history buff, the continent was fully peopled by the advent of the 20th century, and the American mystique began to shrink with the absence of unexplored land. However, those enamored of the primeval American experience can find comfort in a system of north-south trails designed to recapture the natural wonders of the continent, and to provide an escape from commercialism and the inherent noise of the city. The Pacific Crest Trail travels in one form or another from Canada to Mexico, while the Continental Divide Trail lies nearer the center of the county, following some of the highest points of the Rocky Mountains. Most iconic of the major American pathways is the Appalachian Trail that completes the "triple crown" of the national hiking experience. Covering a range from central Maine to Georgia at a distance of 2,193 miles, it is the longest of the three, following the crest of the Alleghenies and Blue Ridge Mountains through 14 states. All in all, it encompasses 465,000 feet in elevation and hosts three million visitors each year for at least a part of the total distance. On an annual basis, approximately 4,000 hikers begin a south to north trek beginning at Springer Mountain, Georgia, with the goal of hiking all the way to Maine. The northerly direction is greatly preferred, in part because of the weather calendar and because the northern terminus closes in mid-October, creating a difficulty for slow travelers.