Volume 8 No. 2 – August 1, 1935
All material courtesy of the National Park Service.These publications can also be found at http://npshistory.com/
Nature Notes is produced by the National Park Service. © 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.