he near neighborhood in
1903 and 1904. The same volcanic impulse which found its main relief in
the explosive eruption of near-by Katmai in 1912 no doubt cracked the
deep-lying rocks beneath this group of valleys, exposing superheated
rocks to subterranean waters which forthwith turned to steam and forced
these vents for escape. Griggs reports that volcanic gases mingle freely
with the steam.

The waters may have one or more of several sources; perhaps they come
from deep springs originating in surface snows and rains; perhaps they
seep in from the sea. Whatever their origin the region especially
interests us as a probably early stage of phenomena whose later stages
find conspicuous examples in several of our national parks. Some day,
with the cooling of the region, this may become the valley of ten
thousand hot springs.

But it is useful and within scientific probability to carry this
conception much further. The comparison between Katmai's steaming
valleys and the geyser basin of Yellowstone is especially instructive
because Yellowstone's basins doubtless once were what Katmai's steaming
valleys are now. The "Valley of Ten Thousand Smokes" may well be a
coming geyser-field of enormous size. The explanation is simple.
Bunsen's geyser theory, now generally accepted, presupposes a column of
water filling the geyser vent above a deep rocky superheated chamber, in
which entering water is being rapidly turned into steam. When this steam
becomes plentiful enough and sufficiently compressed to overcome the
weight of the water in the vent, it suddenly expands and hurls the water
out. That is what makes the geyser play.

Now one difference between the Yellowstone geyser-fields and Katmai's
steaming valleys is just a difference in temperature. The entire depth
of earth under these valleys is heated far above boiling-point, so that
it is not possible for water to remain in the vents; it turns to steam
as fast as it collects and rushes out at the top in continuous flow. But
when enough thousands of centuries elapse for the rocks between the
surface and the deep internal pockets to cool, the water will remain in
many vents as water until, at regular intervals, enough steam gathers
below to hurl it out. Then these valleys will become basins of geysers
and hot springs like Yellowstone's.

VIII

MOUNT RAINIER, ICY OCTOPUS

MOUNT RAINIER NATIONAL PARK, WEST CENTRAL WASHINGTON. AREA, 324 SQUARE
MILES

I

Mount Rainie