A large portion of the river is in a latitude where it freezes over every winter. During the ice period it is indeed effectually enchained. The banks are safe for a season, and the water itself becomes comparatively clear. But as soon as the breezes of spring soften the ice the river resumes its customary wanderings, with renewed vigor after its long rest. By way of celebration of its release from its icy prison it frequently gives exhibitions of power that far surpass all its other manifestations. When the ice “breaks” and begins to “run,” it is liable to strand like a steamboat on the shallow bars. Other ice following, and finding the way obstructed, piles up on that before it. Gradually, sometimes, and sometimes rapidly, the accumulation spreads, cutting off the channel of the river, until, as often happens, it forms a veritable dam across the entire stream. These ice “gorges” develop a power that nothing can withstand, and the amount of property destroyed by them in the history of the river has been very great. There is almost nothing that can be done to break them. Dynamite explosions are resorted to, but the ice piles up so rapidly and in such vast quantities that the most powerful blast seems harmless. In the face of this appalling danger man is forced to stand a helpless spectator until the river itself accumulates sufficient force to burst through the dam. It has more than once happened that, before the dam has given way, the river has cut an entirely new channel. [Sidenote: ICE GORGES.] The moving of the ice, even when not accompanied by serious blockades, is always an impressive sight. Usually the warm weather loosens it from the shore before it begins to move, and even disintegrates it, so that it is unsafe to cross upon. The softer it becomes before it begins to run the less danger is there of its gorging. After the movement begins it continues for several days, until the vast quantities of ice stored in the river above have floated by, or melted away. During the height of the movement the crushing of innumerable ice cakes upon each other produces a continuous roar which can be heard for a long distance from the river. To the lonely dwellers of the valley in the early times the annual “break-up” of the ice was the most welcome event of the year, for it was the knell of the long and tedious winter, and the certain harbinger of approaching spring. [Sidenote: ANNUAL FLOODS.]