Adirondack Mountains, New York.] Some kinds of wood are so heavy that they will not float at all, and some sink so readily that it does not pay to transport them by river.
In such cases temporary railways are usually resorted to.
[Illustration: Fig.24.Hauling Logs by Mules.

Oscilla, Georgia.] On the Pacific coast, where the forests are dense, the trees of enormous size, and no ice road is possible, still other special methods have been devised.

On so great a scale are the operations conducted that they may properly be called engineering feats.

Consider for a moment the size of the trees: red fir ranges from five to fifteen feet in diameter, is commonly two hundred fifty feet high, and sometimes three hundred twenty-five feet high.

The logs are commonly cut twenty-five feet long, and such logs often weigh thirty to forty tons each, and the logs of a single tree may weigh together one hundred fifty tons.