Trees, like men, often rear their structures upon the ruins of those that have gone before. This is an old, old world. In the words of Omar,--
"When You and I behind the Veil are past, Oh, but the long, long while the World shall last."
Is the volcanic curtain once more to fall upon the forests of this magic scene?
In "Our National Parks" John Muir comments eloquently upon the fossil forests and the telling background of most Yellowstone landscapes. He says:--
Yonder is Amethyst Mountain, and other mountains hardly less rich in old forests, which now seem to spring up again in their glory; and you see the storms that buried them--the ashes and torrents laden with boulders and mud, the centuries of sunshine, and the dark, lurid nights. You see again the vast floods of lava, red-hot and white-hot, pouring out from gigantic geysers, usurping the basins of lakes and streams, absorbing or driving away their hissing, screaming waters, flowing around hills and ridges, submerging every subordinate feature. Then you see the snow and glaciers taking possession of the land, making new landscapes. How admirable it is that, after passing through so many vicissitudes of frost and fire and flood, the physiognomy and even the complexion of the landscape should still be so divinely fine!
The Yellowstone Park is about equal in area to Delaware and Rhode Island combined. It has 3300 square miles. The average altitude is 7500 feet, while numerous peaks rise from 1000 to 3000 feet higher. Forests cover 85 per cent of the area.
The largest parklike grassy space in this forested realm lies to the northeast of Mount Washburn, along the valleys of the Yellowstone and Lamar Rivers. This open space is about twenty-five miles long and from five to ten miles wide. The second largest area of grassy country, Hayden Valley, lies several miles to the north of Yellowstone Lake. Among other open spaces are Swan Lake Flat, Gibbon Meadows, Pelican Valley, and the small ragged areas around the Firehole Geyser Basin and Shoshone and Lewis Lakes.
Among the trees are the quaking aspen, Douglas spruce, Engelmann spruce, and subalpine fir. The overwhelming proportion of these forests, however, consists of that interesting tree, the lodge-pole pine. It bears seed every year, beginning while young and small. It hoards its seeds by keeping its tightly closed cones. When fire sweeps through a forest of lodge-pole pine, it kills the trees and melts the sealing-wax of the cones, releasing the seeds. These seeds fall upon shadeless, ash-covered ground, under conditions most favorable to their germination and growth. The lodge-pole pine is Nature's selected agent for reforestation.