feet—Hot springs—Mud geysers. Mount McKinley South 2,645 Highest mountain in North 1917 central America—Rises higher above Alaska. surrounding country than any other mountain in the world. Grand Canyon North 1,009 The greatest example of erosion 1919 central and the most sublime spectacle Arizona. in the world. Lafayette Maine coast. 12 The group of granite mountains 1919 upon Mount Desert Island. Zion Southwestern 120 Magnificent gorge (Zion 1919 Utah. Canyon), depth from 1,500 to 2,500 feet, with precipitous walls—Of great beauty and scenic interest. THE FOSSIL FORESTS OF THE YELLOWSTONE NATIONAL PARK. By F. H. Knowlton, _United States Geological Survey._ INTRODUCTION. Isolated pieces of fossil wood are of comparatively common and widespread occurrence, especially in the more recent geological deposits of the West. Not infrequently scattered logs, stumps, and roots of petrified or lignitized trees are brought to light, but only exceptionally are they so massed and aggregated as to be worthy of the designation of fossil forests. Examples of such are the celebrated fossil forests of relatively late geological age near Cairo, Egypt, the huge prostrate trunks in the Napa Valley near Calistoga, Cal., and the geologically much older and far more extensive forests now widely known as the Petrified Forest National Monument in Apache County, Ariz. But in many respects the most remarkable fossil forests known are those now to be described in the Yellowstone National Park. In the forests first mentioned the trunks and logs were all prostrated before fossilization, and it is perhaps not quite correct to designate such aggregations as veritable fossil forests, though they usually are so called. In the fossil forests of Arizona, for example, which are scattered over many square miles of what is now almost desert, all the trunks show evidence of having been transported from a distance before they were turned to stone. Most of them are not even in the position in which they were originally entombed, but have been eroded from slightly higher horizons and have rolled in the greatest profusion to lower levels. As one views these Arizona forests from a little distance, with their hundreds, even thousands, of segments of logs, it is difficult to realize that they are really turned to stone and are now exhumed from the earth. The appearance they present (see fig. 1) is not unlike a “log drive” that