What the fall of snow is in the upper Park has never been determined; but at Mammoth Hot Springs, altitude 6,200 feet, an average for six years, from November to April inclusive, is ten feet per year, with a maximum of fifteen feet and a minimum of five. But on the Park Plateau, 1,000 to 1,500 feet higher, the fall is certainly much greater. No doubt its light depth aggregates twenty feet. The weight of this snow often destroys the railing of bridges and injures the buildings of the Park. The drifts accumulate in phenomenal magnitude. No matter how deep a ravine may be, the wind will pile the snow up in it until it is level with the surrounding country. Some of these drifts on the mountain sides are hundreds of feet deep and never entirely melt away. Even on the general plateau they last until the middle of July. The Cañon Hotel is almost buried every winter. The snow actually reaches the second story windows, and the drift behind the hotel would last throughout the summer were its melting not facilitated by cutting it in pieces with shovels. It verily seems that all the conditions of climate here conspire to make this region one of the snowiest in the world. Of course, general access to the Park under such conditions is wholly out of the question. Only on snow-shoes is it possible at all. The hotel company has a watchman at each of its buildings, who drags out a lonely existence through the two hundred days from November to May. He can talk over the telephone line with Mammoth Hot Springs, and at long intervals he receives a call, and perhaps mail, from "Telephone Pete," who travels the line to keep it in order. In some places, also, small squads of soldiers are stationed for the winter. The art of traveling by snow-shoe is a thoroughly interesting one, notwithstanding the fact that it is about the most difficult method of travel known and is rarely resorted to except from sheer necessity. The instrument used in the Park for this purpose is called a _ski_ (pronounced skee). It is a long slender strip of wood--ash, Norway pine, or hickory--some twelve feet long, four or five inches wide, and just thick enough to give needed strength. About midway of its length is a strap through which the toe is slipped and by which the foot pulls the _ski_ along. The bearing surface of the two _skis_ is about eight square feet, and holds the weight of the body even in soft snow without sinking more than a few inches. The bottom surface is polished smooth and then rubbed with a mixture of tallow and beeswax to make it free from friction. A pole is an important accompaniment, aiding to slide the traveler along and steady him on the _skis_. It also serves as a brake in descending steep hills, the traveler sitting astride it and bearing the rear end into the snow.