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Washburn
Report Index
YELLOWSTONE EXPEDITION OF 1870
Page 15
with grassy margins, a slow current, and spread out
to a width of from 200 to 400 feet. The bottom is pebbly or quicksand, the
water of crystal clearness, and cold again. The little valley is marshy, for
which reason we traveled on the slopes of the ridges, crossing at intervals
open glades between them. Through one of these flows Alum Creek, a small
stream coming in from the west, its bed dyed of an inky blackness by the
deposit from its strongly impregnated waters. Six miles above the falls we
entered a wide valley of calcareous formation, open and branching among
timber ridges on either side of the river, which runs through its center in
a northeast course, an old lake bed, as are all the grassy sections of the
basin. On the north side of the river appeared the great steam jets before
alluded to, in ravines opening into this valley. A good-sized stream, known
as Hellroaring River, emptied in near by from the north. From the southwest
a shallow stream came in also, and in front, near the center of the valley,
were several large white hills to which we directed our course. Elk were
feeding in small bands on the other side of the valley, and large flocks of
water fowl were frequently seen sporting in the river channel. The white
hills, or the "Seven Hills," as we afterward named them, proved well worth a
visit. He is a group of large mounds varying from 200 to 500 feet in height,
each of which has been deposited by the action of a single spring, and at
their basis a system of nature's chemical works on the grandest scale. I
climbed to the summit of the two loftiest of these hills; their formations
are identical, all being composed of calcareous matter, solid within, but
shelly on the exterior, and when decomposed of a snowy whiteness. The slopes
were covered with shales, slid down from above. On the summits were ruins of
craters of great size and former solidity, now choked up with dèbris. From
hydrostatic pressure all the springs had burst out below at the foot of the
slopes, but through innumerable small vents all over the surface of the
hills hot sulphur vapor escaped, subliming around the vents in splendid
crystals of large size. The rocks were everywhere warm, and in some places
hot to the touch; wherever the horses feet broke through the crust hot vapor
escaped. Everywhere the rocks gave forth a hollow sound beneath our tread,
and in many places the intense heat caused them to bulge out in a scaly
formation, which broke through on the slightest pressure of the foot,
whereupon scalding vapor poured out in such volumes as to cause a hasty
retreat. The greatest spring in appearance lies at the base of the highest
hill and is intensely sulphurous, great clouds of vapor constantly escaping.
It measure 15 by 20 feet on the inside; the water boils up constantly from
three to seven feet in height, the whole surface rising and falling
occasionally with a flux and reflux of four feet additional, overflowing its
basin and receding every few minutes. The basin is built up with a solid rim
or lining or pure crystalline sulphur, four feet in width all around the
edge, probably amounting to forty tons in weight. The water is clear, but of
a whitish cast, and above the boiling point, steam being evolved from its
surface. The basin cannot be approached nearer than 20 feet distant on
account of the scalding vapors. A small channel leads down the slope and for
several hundred feet its bed is incrusted with a sulphur deposit, showing
that the spring occasionally flows a considerable quantity of water. This
deposit is from three to ten inches deep. Farther along the base of the same
hill is a sulphurous cavern 20 feet in visible depth and 8 feet in diameter,
out of which issued jets of vapor with a sound like the puffing of a
high-pressure steamboat. These jets pulsate regularly, and the vapor is
intensely hot. Scattered along the bases of the next hills
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