A climbing route is a path by which a climber reaches the top of a mountain, rock, or ice wall. Routes can vary dramatically in difficulty and grade; once committed to that ascent, it can sometimes be difficult to stop or return. Choice of route can be critically important. Guidebooks, if available, are helpful in providing detailed diagrams and photographs of routes. In the earliest days of hillwalking and mountaineering, climbers got to the top by whatever means got them there. Little information about how they did it is available. During the 19th century, as explorers of the Alps tried ever harder summits, it became clear that choosing an eastern face over a southwestern ridge could spell the difference between success or failure. One example was the first ascent of the…