Prismatic Lake, a spring large enough to be called at least a lakelet or pond, is a combination of the artistic and the spectacular. It has built up for itself a rounded mound, and down the gently curving slopes flow its waters in thousands of interlacing rivulets. Over the pool hangs a cloud of steam, often tinted red by reflection from the waters below.

[Ill.u.s.tration: MAMMOTH HOT SPRINGS YELLOWSTONE NATIONAL PARK]

At Mammoth Hot Springs, close to Fort Yellowstone, the water bursts from the mountain-side with an enormous mineralized flow. Here lime in solution is quickly precipitated, forming basins and terraces and slopes of exquisite design, the whole adorned with intricate and fantastic fretwork of pink, brown, yellow, and white.

While the deposits here are chiefly lime or travertine, those of the geysers and of the other hot springs are silica. The two kinds of deposits differ greatly. The Mammoth Hot Springs' deposits are soft and frequently change their form. The silica deposits of the geysers are hard as flint. Without this hardness, the geyser action would be impossible, as the lime and travertine formations would not withstand the explosive violence. A curious fact in this connection is that the color in and around the geysers and hot springs is in part due to the presence of algae, a minute vegetable growth.

The geyser is one of Nature's strangest freaks. These in the Yellowstone Park are the largest, most spectacular, and most artistic in the world. The geyser may be described either as a large intermittent hot-water fountain or as a small water-and-steam volcano.

There are scores of these eruptive springs in the Yellowstone, and their irregularities form part of their fascination. The place and method of applying the heat, the diameter and shape of the tube, and the point of inflow and the quant.i.ty of the water are all matters affecting their activities. Apparently they, as well as the springs in general, have no underground interconnection, since the play of one geyser has no effect upon others close by.

The eruptions are irregular as to intervals. Black Warrior and Hurricane do a continuous performance. Constant pauses from twenty to fifty-five seconds between gushes. Grand is active at intervals of from one to four days, and Turban plays intermittently for twenty-four hours following Grand. Giantess rests from five to forty days at a time. Lioness played once in each of the years 1910, 1912, and 1914.

Splendid, which formerly threw a ten-minute gush to a height of two hundred feet, has not played since 1892.

There is equal variation in the duration of the gush. The Minute Man's activity lasts but from fifteen to thirty seconds. Giant stops work promptly at the end of an hour. Giantess, after her long rest, plays from twelve to thirty-six hours.

The quant.i.ty of water erupted varies from a few gallons in the small geysers to thousands of barrels in the large ones. The water is generally thrown vertically, though some of the tubes lie at an angle.

The Fan, as its name suggests, throws its water in a fan-like shape.

Geysers vary in the height of their gush as in everything else, and the gush of each is seldom twice the same. Jewel varies from five feet to twenty, and Great Fountain from seventy-five to one hundred and fifty feet.

The highest stream is thrown by Giant, which has a minimum of two hundred and a maximum of two hundred and fifty feet. Excelsior, which sometimes threw its water three hundred feet into the air, has not played since 1888.

This geyser action is novel, picturesque, and weird. It appeals to the imagination. It goes on day and night, summer and winter, throughout the years. While many of the geysers are comparatively new, others are centuries old. Some may have been playing since prehistoric times.

Old Faithful, in the Upper Geyser Basin, is in most respects the most wonderful geyser in the Park. Its action is almost uniform; its usual interval is seventy minutes. It plays for four minutes and sends its water up from sixty to one hundred and twenty feet. It gives ample warning before each play and gets into action by sending its water higher and higher with graceful ease.

[Ill.u.s.tration: OLD FAITHFUL GEYSER YELLOWSTONE NATIONAL PARK]

But in some particulars Great Fountain, in the Lower Geyser Basin, may be put at the head of the geyser list. Its waters issue from a vast low mound, and the basin has attractive ornamentation. It spouts an enormous volume of water, sometimes to a height of one hundred and fifty feet, and plays from forty-five to sixty minutes, at intervals of eight to eleven hours.

Castle Geyser, in the Upper Geyser Basin, throws only a moderate gush about seventy-five feet in height, but it has built up a most imposing crater. It is quiet for from four to seven days; it then plays three or four times at half-hour intervals.

Other geysers that the visitor may well see are Grand and Beehive, both in the Upper Geyser Basin. Grand plays for about an hour at intervals of from one to four days and throws a column of steaming water smoothly to a height of two hundred feet. Of all the geysers, Beehive perhaps approaches nearest to artistic perfection. From a small, beehive-like mount it sends up a slender column of water vertically and symmetrically two hundred feet.

Yellowstone Lake lies at an alt.i.tude of 7741 feet above sea-level. Its area is about one hundred and thirty-nine square miles, and its irregular sh.o.r.e-line has a length of one hundred miles. In places the lake is three hundred feet deep. There are thirty-six other lakes, of which Shoshone, Heart, and Lewis are the largest. Each has its own peculiar and delightful wilderness boundary and beauty.

There is a close network of streams, of which one hundred and sixty-five have names. Among the more important are Yellowstone, Lamar, Snake, Gardiner, and Firehole Rivers. There are numerous waterfalls and cascades. The extensive water-flow abundantly supplies the headwaters of the Missouri, Yellowstone, and Snake Rivers. In Two Ocean Pa.s.s, among other places, is a lakelet upon the very summit of the Continental Divide whose waters flow to both the Atlantic and the Pacific. The alt.i.tude here is 8150 feet, and the lakelet completes a continuous waterway of nearly six thousand miles from coast to coast.

A map that I carried showed Two Ocean Pond on the Continental Divide to the west of the Thumb. There is a Two Ocean Pond on the Divide at that place as well as one to the south of the lake. But my map did not show that the Divide was horseshoe-shaped, and it located the pond on the wrong arm of this horseshoe. Consequently I had a long search before I found the pond, and much confusion with the topography and watersheds after I had discovered it.

One day in 1891 I had the good fortune to come upon General Hiram M.

Chittenden. He was directing the cutting of trees at a place that has since become famous as Lake View, from which, perhaps, the best view of Yellowstone Lake is to be had. General Chittenden spent many years in the Park and developed its existing scenic road system. He was the first to propose that the excess of elk and other game in this and other parks be distributed over the country at cost.

What is the greatest feature in this wonderland whose history began at a camp-fire? The Lower Falls thrilled me more than any other waterfall I ever have seen. The Yellowstone Canon may be called the greatest attraction in this Park. But to me the supreme attraction is the petrified forests.

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 quant.i.ties 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 canons, 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 Canon, 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 pa.s.sed 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 canon of the Yellowstone.

This is the most celebrated canon 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 acc.u.mulations of gray foam.

Into the upper end of this canon 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.

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.

[Ill.u.s.tration: GRAND CAnON FROM ARTIST POINT YELLOWSTONE NATIONAL PARK _Copyright by Haynes, St. Paul_]

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 gla.s.s, 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 Pa.s.s. This rugged, narrow pa.s.s 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 pa.s.s. The tree-sprinkled, gra.s.sy 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.

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.

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.

[Ill.u.s.tration: PETRIFIED FORESTS IN AMETHYST MOUNTAIN YELLOWSTONE NATIONAL PARK]

This reveals one of the most appealing geological stories ever uncovered--twelve ill.u.s.trated 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.