Nature Notes From Crater Lake
Volume 8, No. 2, August 1935
The Canyons of Crater Lake
National Park
By Warren D. Smith, Ranger-Naturalist
Canyons, like caverns and craters of
volcanoes, always intrigue the imagination. Everyone who pretends to
know much of anything has, I suppose, heard of the Grand Canyon, and
some have looked into its awful depths and wondered what made it, but
only a few have seen the much smaller canyons of Crater Lake National
Park. While not so deep or awe-inspiring, these latter, because of the
materials into which the streams have carved these comparatively deep
trenches, are in some ways more interesting to the geologist than is the
larger one.
Most canyons have been carved by
running water working through long ages. These in Crater lake Park are
relatively very young.
Also, most canyons are due to streams
working along pre-existing fractures in the rocks. Some are cut in
sandstone and limestone -- relatively soft rocks -- while others are
incised in hard lavas, granites, etc.
Some are somber and gray like Hell's
Canyon in the Snake River, between Oregon and Idaho, others are
brilliantly colored and sculptured like the Grand Canyon, and still
others are black and forbidding like the Black Canyon of the Gunnison in
Colorado. Our little canyons in Crater Lake Park are light colored, in
places creamy white, and not at all forbidding. In fact, in the bottom
of some there are tiny little meadows and beautiful flowers and lush
grass.
In this article, I shall attempt to
describe some of the most striking features and important
characteristics of the following: Godfrey's Glen in Annie Creek; The
Pinnacles in Sand Creek; Llao's Hallway in Whitehorse Creek; Rogue River
Canyon, which, although it lies outside the Park, is a part of the area
intimately related to the Park.
If one comes into the Park from Klamath
Falls up the Annie Creek Road, he will pass, for a part of the time on
his left and part of the time on his right, a deep (200 - 250 feet)
canyon which reaches its finest expression in what is know as Godfrey's
Glen. At a convenient point on the road one can stop his car and look
down to where the canyon of Annie Creek, suddenly widening out, forms
something like a deep glen. A superficial glance reveals creamy walls
shading off here and there into pinkish tones or even grayish black,
along a deep trench out of which tall trees barely emerge. However, a
trip down to the bottom will show much more.
Scrambling down to the bottom and
working up on one of the walls, (it is always better to work upward in
such a place as one will move more slowly and therefore see more), one
notes that the canyon is made up from top to bottom of loose friable
materials, but of such consistency that for several miles the walls are
very steep, in places almost perpendicular. A more careful examination
reveals at least four distinct horizons in which the materials are
different. Although practically all of the material is pyroclastic,
"fire-broken" rocks, at the bottom is a bluish to reddish deposit of
fragmenta. Above this lies a thick deposit of pumice and pumicite and
still higher up in the steeper portion of the canyon wall is a heavy red
bed of dark grayish to black volcanic ash which stand up in bold cliffs.
On top we have 30 to 50 feet of loose pumice and sand with a slight
mixture of clay, just enough to the material will pack somewhat when a
handful of it is firmly pressed. The other materials show little
tendency to do this and are very crumbly.
Just what is this deposit and how came
it to be where it is? Much of the material is extremely light in weight
and porous. Geologists have identified this as pumice and pumicite,
which was a frothy lava of quite acid composition, i.e. high in silica,
ejected from the prehistoric volcanic mountain in a violent explosion.
There is some mud flow debris and
fluvio-glacial was mixed with these deposits, but they are not easily
differentiated without close examination. As a matter of fact, these
valley fillings are of very composite nature, consisting of pyroclastics
thrown out during eruptions of pelean type with burning cloud, glacial
flour, mud flows, ashes, and cinders, and finally wash from the side
hills. A close examination of some parts of these canyon walls reveals a
pudding-like mass of heterogeneous materials, broken lava fragments,
some angular, others somewhat rounded, boulders of pumice, and ash quite
without definite arrangement or stratification, all together giving one
the impression of a hasty pudding. A rough cross-section of the Annie
Creek Valley and canyon is shown in the diagram, Fig. I.

When it came down over the country
side, this material was pretty hot and was mixed with water and other
substances more or less fluid. Later it cooled and dried out to some
extent. This desiccation resulted in contraction and the formation of
great shrinkage cracks, rough approximation to the columnar jointing in
basalt, generally vertical, along which percolating water from above
have found it easy to erode the mass. This erosion along these fractures
or joint planes has resulted in the formation of rather sharp pinnacles.
Occasionally, one finds a boulder or bit of harder more firmly cemented
material as a capping on some of the pinnacles resembling a bishop's hat
perched on a small head and scrawny neck. This "hat" acts as a
protection to the column and saves it from more rapid erosion.
Godfrey's Glen is just a small portion
of a canyon some seven or eight miles long, which varies in width from a
hundred feet to several hundred and in depth from about one hundred to
two hundred and fifty feet or more. Some small chutes and a few water
falls are found along it where the stream has encountered slightly
harder materials. One of the best of these is at the head of Godfrey's
Glen, and is known as Dewie Falls.
In Wheeler Creek, a tributary of Sand
Creek, a mile or so below the East Entrance to the Park, we have pretty
much the same formation, but here the pinnacles are even better
developed than in Godfrey's Glen.
To realize the real beauty of these
canyons, one should not be content to look at them from above merely,
but should descend to the bottom and look up at the tinted walls, (the
deepest coloring is due to iron oxide stains), and at the tall majestic
trees that struggle to reach above the rim. Here we have a scene
altogether different from the majestic beauty of Crater Lake, but one
that is very satisfying to the nature lover who likes the quieter, less
spectacular aspects of the extremely variegated terrain of the Park.
In Llao's Hallway, we have a curious
little canyon out in the same sort of materials found in the others
mentioned, but much smaller and more weird. As one threads his way down
this tortuous passageway, he may have the impression of passing down
through a giant burrow of some subterranean monster, or in places he
finds that he is in a tube with a narrow crack in top. The Hallway is
only about a quarter of a mile long and in the summer is dry, being cut
entirely in pumice, and mud flow debris. In places the walls overhang
and the view of the sky is completely shut off. It has been well named
and one can easily imagine the great Indian God of Evil who lived in the
hot lake, (before Crater lake cooled off), strolling or hurrying down
this maize-like passageway on some evil mission.
People who intend to explore this
interesting feature of the Park, (which is located in Whitehorse, a
tributary of Castle Creek), should be sure not to be caught in there
during a thunder storm as it is almost impossible to get out of the long
passage until one has reached the end. Also, one should be on the look
out for falling stones from above. Fortunately, these are mainly light
pumice and do not weigh very much, but even a big chunk of pumice on top
of one's head can cause a good headache.
Space does not permit any more detailed
description of some of these interesting places. Furthermore, if the
reader has access to Nature Notes files of earlier years, he will
find an article on the pinnacles by the then Park Naturalist, D. S.
Libbey, in Vol. IV No. 3, (September 1931), and one on Llao's Hallway by
W. G. Moody, Acting Park Naturalist, in Vol. VI, No. 2 (July 1933).
We should say a word about the Rogue
River and its canyon stretches just by way of contrast to those in the
Park since the traveler will be coming or going into the Park at some
time by the Medford Road and he will glance down perchance into some of
the yawning chasms cut by this fine river. In the upper reaches the
Rogue has worked down into much the same character of deposits we find
in the other canyons names, but when one gets lower down toward the
Medford country he finds the river cutting into solid rock. This rock is
a lava, but an older and denser lava than is to be seen at Crater Lake.
It is a basalt. One big query arises here in passing -- one which
is often asked us on duty at the Rim -- "Did this lava in the Rogue
River canyon flow out of the side of Mt. Mazama when it collapsed?" If
this were so, our problem of the destruction of Mt. Mazama would be
solved. Unfortunately we must say no. This is an older basalt of Miocene
age and is perhaps the equivalent of the Columbia Lava Plateau.
Just outside the Park to the southwest
of Crater Lake, the country drops off rapidly into another canyon in
this older basalt. The name of this is Red Blanket.
To some, canyons are merely gloomy and
forbidding, others find them occasionally attractive, but the geologist
finds them useful. The reason for this is that the geologist wants to
know what is below the surface and ordinarily he cannot penetrate more
than an infinitesimal part of the distance into the interior of the
earth by drilling or digging, so when Nature has provided a natural,
deep section into the outer crust of the earth, he can examine the
materials exposed by this incision and thereby draw much clearer
deductions than if he were looking at the surface merely and guessing at
what lies beneath. Therefore a geologist, if he is a conscientious
worker, will examine carefully every deep cut in the earth. This is the
chief interest that such canyons as we have in the Park hold for us who
are geologically inclined. Just as a surgeon has often times to make a
deep incision into the body to locate the source of trouble or the
anatomist makes sections of tissue, so do we rely upon those natural
sections. However, in the body of the earth of course, we cannot for the
lack of time, means, and power, hope to make artificial incisions into
the earth or begin to do what the streams have done for us. We must rely
upon every and all such natural sections.
From the foregoing, it is hoped the
reader will obtain a respect for our canyons, their interesting
features, their beauty, even though at times, awesome, and finally their
great utility in deciphering the story of the past in this and all other
regions where the pages of certain chapters of the Book of Rocks remain
to be cut and deciphered.