Chapter 5 THE PETRIFIED FORESTS

Volcanic outpourings have ended the life of many extensive Yellowstone forests. In Amethyst Mountain are twelve forests, one above the other, buried at different periods by volcanic eruptions. On top of this mountain the pines and spruces are merrily growing, unmindful of the buried past-of the tragic tree history beneath. Nature forgets. Ages ago, the lowest of these entombed forests grew on the mountain plateau in the sunlight. But a flow of volcanic mud and heavy showers of ashes overwhelmed and buried it, with the trees standing erect.

This volcanic material added a layer to the plateau. In the new surface above the buried and forgotten forest, another tree growth flourished and towered. But the volcanoes only slept. Again their fire and ashes filled the sky, and again the forest was overwhelmed. Thus through the ages-through "a million years and a day"-each time the volcanoes slept the pines peeped up, and again their shadows fell upon the desolate lava landscape.

PETRIFIED FORESTS IN AMETHYST MOUNTAIN

YELLOWSTONE NATIONAL PARK

At last, twelve or more forests were buried, each as it had stood upon the mountain, and in a layer by itself. The material in these numerous fateful volcanic outpourings raised the summit two thousand feet.

It may be that the topmost of these petrified forests was overwhelmed by the Ice King, but a volcano entombed the others. All were petrified, fossilized, or opalized. During the ages that went by, the Lamar River and other factors eroded a wide valley and excavated the edges of these forest ruins.

This reveals one of the most appealing geological stories ever uncovered-twelve illustrated but unwritten chapters of world-building.

The strata of these twelve forests, story above story, show their edges in the precipitous northern face of Amethyst Mountain. Thousands of logs and stumps still partly buried jut and bristle.

Apparently there is an enormous area of these buried fossil forests in the northeast part of the Park, and perhaps numerous areas elsewhere in the region. They are also known to exist near the northwest boundary of the Park.

Mineralized water circulated through and gradually fossilized the buried trees, changing many to opal. In due time the mud and ashes that buried these trees also turned to stone. Limbs and tops of trees were broken off by the ashes, cinders, and mud that buried each forest. Many tree-trunks were overthrown, but great numbers were entombed as they stood. They are from one to ten feet in diameter, and some were of great height. Many of the remaining stumps project forty feet.

Much of the opalized wood is very beautiful. The change brightened and intensified the former texture of the wood. In most of these stone trees and logs the annual rings show clearly. They distinctly reveal the age of the tree and its rapidity of growth. In many cases the species is readily determined. Strange stories are told by the fallen logs, in many of which old worm-holes show. The half-decayed logs were preserved in their original form, and in the process of fossilization their hollow interiors were filled with beautiful rosettes and crystals.

Each of the buried forests contained some trees of different species from those in the forest just beneath it. Altogether, more than eighty kinds have been recognized. Many of these would grow only in a mild or subtropical clime, so the former climate of this region must have been warmer than at present. Among the trees were redwood, cottonwood, walnut, pine, oak, sycamore, fig, magnolia, and dogwood.

Ancient Troy was nine ruined cities deep. But here in a national playground of our own country are twelve tree cities in ruins, one above another, and topped with a city of living trees. Like the excavated ruins of Pompeii, these ruined forests set one's mind to exploring the realm of imagination. Here in a subtropical clime, possibly a million years ago, was a luxuriant forest. Beneath was a crowded undergrowth of plants, of shrubbery and waving ferns. Gay butterflies may have flitted here in the golden sunshine. Trees enjoyed the storms and lifted their heads serenely into the light. Then came the tragic end. Twelve times or more was this impressive drama re?nacted.

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!