Mountaineering Routes : Page 311

Icefield.—Two problems are provided by an icefield: Its crevasses are usually snow-covered and difficult to detect. Wherever this situation exists, the party must be roped, with a good interval between men, and should follow a route perpendicular to the crevasse system so that no more than one man will be, unsuspectingly, over the same crevasse. The second problem is that of maintaining route when, as frequently happens, a fog or blizzard settles down on the icefield. If weather threatens, route markers (willow wands 36 in. X 1/4 in. with red flag on which back azimuth may be marked) should be placed along the route, each succeeding wand being retrieved on the return as soon as the next one has been found. The skier should remember that a cloudless sky does not necessarily mean a fogless icefield later in the day, and that tracks may be either quickly melted in wet snow or quickly covered by windblown powder.