With the new order of travel began a new conception of the Yellowstone's public usefulness. It ceased to be a museum of wonders and began to be a summer pleasure-ground. Instead of the fast automobile-stage decreasing the average length of visit, the new idea which it embodied has lengthened it. This new idea is a natural evolution which began with the automobile and spread rapidly. The railroads had been bringing tourists principally on transcontinental stop-overs. Automobiles brought people who came really to see the Yellowstone, who stayed weeks at public camps to see it, or who brought outfits and camped out among its spectacles. The first Ford which entered the park on the morning of August 1, 1915, the day when private cars were first admitted, so loaded with tenting and cooking utensils that the occupants scarcely could be seen, was the herald of the new and greater Yellowstone. Those who laughed and those who groaned at sight of it, and there were both, were no seers; for that minute Yellowstone entered upon her destiny.
The road scheme is simple and effective. From each entrance a road leads into an oblong loop road enclosing the centre of the park and touching the principal points of scenic interest. This loop is connected across the middle for convenience. From it several short roads push out to special spectacles, and a long road follows Lamar Creek through a northeastern entrance to a mining town which has no other means of communication with the world outside. This is the road to Specimen Ridge with its thirteen engulfed forests, to the buffalo range, and, outside the park boundaries, to the Grasshopper Glacier, in whose glassy embrace may be seen millions of grasshoppers which have lain in very cold storage indeed from an age before man. All are automobile roads.
II
The hot-water phenomena are scattered over a large area of the park. The Mammoth Hot Springs at the northern entrance are the only active examples of high terrace-building. The geysers are concentrated in three adjoining groups upon the middle-west side. But hot springs occur everywhere at widely separated points; a steam jet is seen emerging even from the depths of the Grand Canyon a thousand feet below the rim.
The traveller is never long allowed to forget, in the silent beauty of the supreme wilderness, the park's uncanny nature. Suddenly encountered columns of steam rising from innocent meadows; occasional half-acres of dead and discolored brush emerging from hot and yellow mud-holes within the glowing forest heart; an unexpected roaring hillside running with smoking water; irregular agitated pools of gray, pink, or yellow mud, spitting, like a pot of porridge, explosive puffs of steam; the warm vaporing of a shallow in a cold forest-bound lake; a continuous violent bellowing from the depths of a ragged roadside hole which at intervals vomits noisily quantities of thick brown and purple liquid; occasional groups of richly colored hot springs in an acre or more of dull yellows, the whole steaming vehemently and interchanging the pinks and blues of its hot waters as the passing traveller changes his angle of vision—these and other uncouth phenomena in wide variety and frequent repetition enliven the tourist's way. They are more numerous in geyser neighborhoods, but some of them are met singly, always with a little shock of surprise, in every part of the park.
The terrace-building springs in the north of the park engulf trees. The bulky growing mounds of white and gray deposit are edged with minutely carven basins mounted upon elaborately fluted supports of ornate design, over whose many-colored edges flows a shimmer of hot water. Basin rises upon basin, tier upon tier, each in turn destined to clog and dry and merge into the mass while new basins and new tiers form and grow and glow awhile upon their outer flank. The material, of course, is precipitated by the water when it emerges from the earth's hot interior. The vivid yellows and pinks and blues in which these terraces clothe themselves upon warm days result from minute vegetable algæ which thrive in the hot saturated lime-water but quickly die and fade to gray and shining white on drying. The height of some of these shapeless masses of terrace-built structures is surprising. But more surprising yet is the vividness of color assumed by the limpid springs in certain lights and at certain angles.
Climbing the terraces at the expense of wet feet, one stands upon broad, white, and occasionally very damp plateaus which steam vigorously in spots. These spots are irregularly circular and very shallow pools of hot water, some of which bubble industriously with a low, pleasant hum. They are not boiling springs; the bubbling is caused by escaping gases; but their waters are extremely hot. The intense color of some of these pools varies or disappears with the changing angle of vision; the water itself is limpid.
Elsewhere throughout the park the innumerable hot springs seem to be less charged with depositable matter; elsewhere they build no terraces, but bubble joyously up through bowls often many feet in depth and diameter. Often they are inspiringly beautiful. The blue Morning Glory Spring is jewel-like rather than flower-like in its color quality, but its bowl remarkably resembles the flower which gives it name. Most springs are gloriously green. Some are the sources of considerable streams. Some stir slightly with the feeling rather than the appearance of life; others are perpetually agitated, several small springs betraying their relationship to the geysers by a periodicity of activity.