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 algae 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 s