The Chinook blows occasionally over the Northwest during the five colder months of the year. Though of brief duration, these winds are very efficacious in softening the asperities of winter with their moderating warmth, and they are of great assistance to the stock and other interests. Apparently the Chinook starts from the Pacific, in the extreme Northwest, warm and heavily moisture-laden. Sweeping eastward, it is chilled in crossing the mountains, on which it speedily releases its moisture in heavy snowfalls. Warmed through releasing moisture, it is still further warmed through compression while descending the Cascades, and it goes forward extremely feverish and thirsty. It now feels like a hot desert wind, and, like air off the desert's dusty face, it is insatiably dry and absorbs moisture with astounding rapidity. It may come from the west, the southwest, or the northwest. Its eastward sweep sometimes carries it into Wisconsin, Iowa, and Kansas, but it most frequently floods and favors the Canadian plains, Oregon, Washington, Montana, Idaho, Wyoming, and Colorado. It may come gently and remain as a moderate breeze or it may appear violently and blow a gale. Its duration is from a few hours to several days. There are numerous instances on record of a Chinook greatly raising the temperature, removing several inches of snow, and drying the earth in an unbelievably short time. An extreme case of this kind took place in northern Montana in December, 1896. Thirty inches of snow lay over everything; and the quicksilver-tip in thermometers was many lines below zero. In this polar scene the Chinook appeared. Twelve hours later the snow had entirely vanished! The Blackfoot Indians have a graphic term for this wind,--"the snow-eater." In most respects this wind is climatically beneficial. A thorough warming and drying a few times each winter renders many localities comfortably habitable that otherwise scarcely would be usable. The occasional removal of snow-excesses has its advantages to all users of roads, both wagon and rail, as well as being helpful to stock interests. There are times when this wind leaves the plains too dry, but far more frequently it prevents terrible floods by reducing the heavy snow covering over the sources of the Columbia and the Missouri before the swift spring thaw appears. The Chinook is not likely to create floods through the rapidity of its action, for it changes snow and water to vapor and carries this away through the air. The Chinook is nothing if not eccentric. Sometimes it warms the mountain-tops and ignores the cold lowlands. Often in snowy time it assists the railroad men to clear the tracks on the summit before it goes down the slope a few miles to warm the muffled and discouraged snow-shovelers in the valley. Now and then a wind tempers the clime for a sheepman, while in an adjoining valley only a few miles away the stockman and his herd wait in vain for the Chinook.