Chapter 4 AGES OF FIRE AND ICE

The Yellowstone plateau is a vast lava-deposit. Its material is mostly volcanic, but its landscape-its architecture-is largely glacial. In ages remote, this realm became the scene of volcanic activity. Intermittent outpourings went on through long periods of time. Volcanoes in and near the Park threw forth quantities of ashes, lava, and cinders, which built up a plateau region three or four thousand feet thick. Rhyolite and other forms of lava were last spread over the region. This volcanic activity appears to have ended before the last ice age. No eruption has occurred for centuries.

The ice age wrought vast changes in the volcanic landscape. The ice smoothed wide areas, shaped ca?ons, and rounded mountain-sides, produced and spread soil, and gave the entire region the flowing, attractive lines of glacial landscape.

On the rim of the Yellowstone Ca?on, about three miles below the falls, an enormous glaciated granite boulder reposes upon lava-rhyolite. It measures about twenty-four by twenty by eighteen feet. It was transported to this resting-place from mountains more than thirty miles away. Here we have a stone foundation laid by volcanic fire, and upon it a stone, shaped, transported, and placed by glacial ice.

There are about three thousand geysers, hot springs, and mud-and-water springs in the Park; and as many other vents of steam, acid, and gas. That the geysers have been active in this region for thousands of years is shown in the deep deposits of silica and travertine that overspread extensive area. During the ice age many of these deposits were eroded and others were piled with boulders. It is plain that steam and hot water had been at work long before the last ice age came. During the ice period, a wild conflict probably took place between the deep outspread ice and the insistent eruptions of steam and hot water.

The surface of Yellowstone Lake once stood about one hundred and eighty feet higher than it is at present. Its outlet was then through the Snake River to the Pacific Ocean. The Continental Divide then passed over the summit of Mount Washburn. Unwritten as yet is the splendid geological story of this change, which may have been caused by earthquake upheaval or by subsidence. It appears to have occurred about the close of the last glacial epoch. Possibly ice dammed the narrow gorge of Outlet Creek, through which the waters of the lake formerly flowed to the Snake River. Whatever the cause, its outlet waters changed and eroded the now famous and splendidly colored ca?on of the Yellowstone.

This is the most celebrated ca?on in the Park, and its colors make it one of the most gorgeously startling in the world. At bright noonday, it is adorned with all the hues of the sunset sky. Its precipitous walls are comparatively free from vegetation and are broken with pinnacles and jagged ridges. About fifteen hundred feet below the edge, the rushing waters of the Yellowstone River take on various shades of blue and green between accumulations of gray foam.

Into the upper end of this ca?on the river, about seventy feet wide, makes a sheer leap of three hundred and ten feet. From the near-by rim, this wonderful waterfall appears like an enormous, fluffy, endless pouring of whitest snowflakes. The magnificence and wildness of its setting combine to make it one of the most imposing waterfalls in the world.

Copyright by Haynes, St. Paul

GRAND CA?ON FROM ARTIST POINT

YELLOWSTONE NATIONAL PARK

The paint-pots are the curiosities of the Park. They are craters, or irregular-shaped ponds, in the earth, filled with brightly colored mud, thick and hot, of fine texture, and in appearance resembling kalsomine or paint freshly mixed and colored. The mud in many pots is red or pink; that in others is lavender, blue, orange, or yellow. Occasionally a rugged vat of this mud is found boiling away-very suggestive of slaking lime. In other cases, plastic mud throbs and undulates as steam-jets now and then escape through it. Here and there this bright steamy mud opens like a full-blown lily. The paint-pots near the Fountain Geyser, those east of the road in Gibbon Meadows, and those close to the lake at the Thumb are the more attractive.

John Muir, in "Our National Parks," says of the Yellowstone:-

Beside the treasures common to most mountain regions that are wild and blessed with a kind climate, the Park is full of exciting wonders. The wildest geysers in the world, in bright, triumphant bands, are dancing and singing in it amid thousands of boiling springs, beautiful and awful, their basins arrayed in gorgeous colors like gigantic flowers; and hot paint-pots, mud springs, mud volcanoes, mush and broth caldrons whose contents are of every color and consistency, plash and heave and roar in bewildering abundance. In the adjacent mountains, beneath the living trees the edges of petrified forests are exposed to view, like specimens on the shelves of a museum, standing on ledges tier above tier where they grew, solemnly silent in rigid crystalline beauty after swaying in the winds thousands of centuries ago, opening marvelous views back into the years and climates and life of the past. Here, too, are hills of sparkling crystals, hills of sulphur, hills of glass, hills of cinders and ashes, mountains of every style of architecture, icy or forested, mountains covered with honey-bloom sweet as Hymettus, mountains boiled soft like potatoes and colored like a sunset sky.

I had lively scrambles and saw much petrified wood in the rough mountainous country at the northwest corner of the Park. But the roughest and most scenic section visited was around Sylvan Pass. This rugged, narrow pass cuts through high, crowding mountains. To the north, Hoyt Mountain and Avalanche Peak rise precipitously; to the south, Grizzly and Top Notch Peaks. Sylvan Lake, whose peculiar wild beauty is unexcelled, is near this pass. The tree-sprinkled, grassy section near the Lamar River, in the northeast corner of the Park, was the most charming and parklike section visited.

The Grand Teton, a peak of towering, bold individuality, looms imposingly as seen from various points in the Park. Its appearance across Yellowstone Lake, from a point near the outlet, is magnificent. Another excellent view of it is obtained from the stage-road midway between Upper Geyser Basin and the Thumb.

The Grand Teton territory might well be added to the Park; likewise a stretch of the rugged, mountainous territory lying along the southeast corner, and the mountainous tract immediately west and north of the northwest corner of the Park. All these belong to reserved government lands, and could without difficulty be administered as a part of this wonderland.