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Studies in the Sierra

by John Muir

[John Muir in 1873]
John Muir in 1873
From a painting by William (Billy) Simms


By William E. Colby

One of John Muir's greatest achievements, in a life filled with remarkable accomplishments, was his early recognition and announcement of the important part played by glaciation in the origin of Yosemite Valley. He first visited the valley in April, 1868, and returned in November, 1869, to live there for the next several years. By the following August he had definitely concluded that a great system of glaciers converging in the Yosemite was responsible for the creation of this mighty gorge with its superb cliffs and falls.

It is not strange that a youth with John Muir's inquiring and scientific mind1 and enthusiasm for the outdoors should have been drawn to the study of this creation problem. To see Yosemite Valley is to wonder how it was made. No one can view the vertical cliffs of El Capitan and Half Dome, with Yosemite and Bridalveil fall plunging out of the sky over other equally sheer walls, with Nevada and Vernal falls leaping down over gigantic steps of solid granite in the Merced River's stately descent to the valley and then wander over that broad expanse of parklike floor without speculating how this exceptional aggregation of impressive scenic features came into existence.

It is true that there have been visitors who were content to attribute this wonder spot of the world to an act of original creation by Providence and to urge that it came into existence "full panoplied," as it were, possessing from "the dawn of creation" all its wondrous glory, and who have insisted that it has remained unchanged to this day. John Muir delighted in telling a story of the occasion when in June of 1879 he was taking a horseback party, including Dr. Joseph Cook, a noted clergyman, up Clouds Rest. The conversation naturally turned to the origin of the scenic wonders spread out before them. Muir had expounded his theory of the part glaciers had played in molding the landscape, and Cook had countered with his view that the valley and its surroundings were not the product of any evolutionary growth, but came into being as they now are, "created out of the hand of God." He favored Whitney's theory, that the bottom of the valley had dropped out, because it fitted in with his own view of creation. The reverend gentleman, who was rather portly, had dismounted and was examining a piece of the glacier-polished granite pavement to which Muir had called his attention, when suddenly his iron-nailed shoes slipped on the glassy surface and he sat down on the solid rock with all his ponderous weight. He was rather dazed by the jolt. Muir rushed over to help him to his feet, but could not refrain from taking advantage of the situation by exclaiming, "Now, Doctor, you see the Good Lord has given you this most convincing proof of the mighty work the glaciers have wrought!"

Concerning the origin of Yosemite Valley much has been written and, in the early days of geologic study, various conflicting theories were advanced.2 Naturally the Sierra Club has, from its organization, been deeply interested in this question. Its first and foremost leader, John Muir, was a major contributor to the ultimate clarification of the problem,3 and to the formulation of modern concepts. The Sierra Club was instrumental in persuading the federal government to undertake, through its Geological Survey, the comprehensive study of the valley by the late François E. Matthes, which in 1930 resulted in publication of the monograph, The Geologic History of the Yosemite Valley.4 More recently, the influence of the Sierra Club led to preparation of a nontechnical volume, "The Incomparable Valley: A Geological Interpretation of the Yosemite," by François E. Matthes (in press).

Professor J. D. Whitney,5 California State Geologist (1860-1874), formulated and sponsored the first theory which received widespread acceptance. He and his staff started work in the fall of 1860 and by 1865 the State of California had published Volume I, "Geology," as a result of four years of field work. In this volume Whitney expounds his theory of the valley's origin (421-423). He stated that the conclusions there given were not only his own but those of his staff as well. He attributed the existence of most of the great valleys and canyons of California to stream erosion, but noted that the vertical walls of El Capitan and the other great cliffs of Yosemite cannot be satisfactorily explained in this manner.

He says:

it appears to us probable that this mighty chasm has been roughly hewn into its present form by the same kind of forces which have raised the crest of the Sierra and moulded the surface of the mountains into something like their present shape. The domes, and such masses as that of Mount Broderick, we conceive to have been formed by the process of upheaval itself, for we can discover nothing about them which looks like the result of ordinary denudation. The Half Dome seems, beyond a doubt, to have been split asunder in the middle, the lost half having gone down in what may truly be said to have been "the wreck of matter and the crush of the worlds."

He added however, that "some of the corps" had objected that there were places in the bottom of the valley which seemed to be of solid granite, whereas, on the theory of engulfment, or dropping down of the great block of granite which originally occupied what is now the valley's void, "there should be an unfathomable chasm, filled now, of course, with fragments, and not occupied by a solid bed of rock." His reply to this was that some of

the masses which have been engulfed may have been of such enormous size as to give the impression where they are only imperfectly exposed, of perfect continuity and connection with the adjacent cliffs . . . this grand cataclysm may have taken place at a time when the granitic mass was still in a semi-plastic condition below, although, perhaps, quite consolidated at the surface and for some distance down.

Pressure, he said, may have united the yielding material and destroyed all traces of fracture and added:

If the bottom of the Yosemite did "drop out," to use a homely but expressive phrase, it was not all done in one piece, or with one movement, [but different sized segments] may hake descended to unequal depths.

It is of more than passing interest to note that he credited Clarence King and James T. Gardiner with obtaining

ample evidence of the former existence of a glacier in the Yosemite Valley, and the canyons of all the streams entering it are also beautifully polished and grooved by glacial action. It does not appear, however, that the mass of ice ever filled the Yosemite to the upper edge of the cliffs; but Mr. King thinks it must have been at least a thousand feet thick.

He mentioned the various glacial moraines which King had traced out in considerable detail on the valley floor and stated that the large terminal moraine, occurring about a quarter of a mile below El Capitan, originally formed a complete barrier across the valley and that it was not unlikely that this may have acted as a dam, thus creating a lake

now filled up with comminuted materials arising from the grinding of the glaciers above, thus giving it its present nearly level surface.

In other parts of this volume Whitney mentioned the evidence of the existence of great glaciers in Tuolumne Meadows and Canyon and in the Kern, Kings, and San Joaquin river valleys. Some of these glaciers he reported to have been over 1,000 feet and even as much as 1,500 feet thick. These data were largely supplied him by Clarence King, who seems to have been much more impressed by the magnitude of these ancient glaciers and their erosive power than was Whitney.6 Only a few years later Whitney, evidently nettled by criticisms of his fault theory and also by suggestions that glacial action was really responsible for the valley's formation, flatly and expressly denied that there was "ample evidence of the former existence of a glacier in the Yosemite Valley," and of glacial moraines which he had previously reported in considerable detail in his volume on the geology of California, as noted above.

In this later publication (1869) he said:

Much less can it be supposed that the peculiar form of the Yosemite is due to the erosive action of ice. A more absurd theory was never advanced than that by which it was sought to ascribe to glaciers the sawing out of these vertical walls and the rounding of the domes. Nothing more unlike the real work of ice, as exhibited in the Alps, could be found. Besides, there is no reason to suppose, or at least no proof, that glaciers have ever occupied the Valley, or any portion of it . . . so that this theory, based on entire ignorance of the whole subject, may be dropped without wasting any more time upon it. [The Yosemite Guide-Book, p. 73.]

This is a most astounding repudiation of observable facts by an eminent scientist. The only rational explanation for this complete about-face was Whitney's intense pique that a geologist with his reputation should have been proved wrong on so important a matter as the valley's origin. Whitney's theory, when announced, had been quite generally accepted as providing a plausible and satisfactory explanation. To have it undermined must have been gall and wormwood to his proud nature, unduly sensitive to criticism as he was.

John Muir was mainly responsible for demonstrating Whitney's theory about the formation of Yosemite Valley was in error and untenable. Arriving in California in the early spring of 1868, he lost no time in visiting Yosemite Valley. He had read of its matchless qualities, and, attracted as if by a magnet, traveled on foot down through the Santa Clara Valley over Pacheco Pass, and crossed the San Joaquin Valley, which was still in its pristine glory, then a veritable sea of wildflowers from one side to the other. Several feet of snow still buried the trails leading into Yosemite Valley, but this did not deter Muir from continuing to his goal. He found the valley to be one of those widely heralded discoveries which really "come up to the brag," as Emerson expressed it when he visited the valley in later years. Fascinated by its majesty and incomparable grandeur, Muir decided then and there to spend much time in those breathtaking surroundings. Earning enough money in the foothills near Merced tending sheep and doing farm work, and accompanying a band of sheep into Tuolumne Meadows in the summer of 1869, he returned to the valley in November to spend the next several years.

Muir's scientific and searching turn of mind was powerfully attracted by the problem of determining the origin of such a remarkable manifestation of nature. His subsequent exploration led into every nook of the valley itself; and, finding that the evidence which was there written on the rocks pointed to the higher mountains, he started out on his memorable excursions into the High Sierra. These he has described with such understanding and enthusiasm that his writings have become literary classics. With infinite patience, on hands and knees where the evidence required close and painstaking observation, and with the aid of his magnifying glass and compass, he accumulated a mass of irrefutable facts concerning glacial action in the Yosemite Valley and the High Sierra.

It is questionable whether, on Muir's first hurried visit to the valley in 1868, when he only spent ten days there, he made many detailed observations. He had previously read Whitney's Geology and learned of his "bottom-dropping-out" theory. Fortunately, we have in Muir's own diary notes of his first studied observations on the subject.7 These notes were made in the summer of 1869 when he was employed to aid in taking a band of sheep ("hoofed locusts," as he later aptly described them because of their destructive effect on the mountain vegetation) from the Merced foothills up into the Tuolumne Meadows. His first glacial notation was made when they were encamped in July on Tamarack Creek. He at once recognized the large boulders there as glacial erratics resting on "ice-planed" granite "scored and striated in a rigidly parallel way." A few days later, when camped on Indian Creek just above Yosemite Valley, he mentioned "the shining glacier pavement . . . the great smooth domes . . . and brushy moraines." While sketching on North Dome, just above the valley, he remarked on "the ice-burnished pavements and ridges" and "glacier-polished domes." From the slopes of Mount Hoffmann he saw "the billowy glaciated fields of the upper Tuolumne" and looked down on Lake Tenaya,

The largest of the many glacier lakes in sight [situated in an] ice-sculptured lake-basin [which] seems to have been slowly excavated by the ancient glaciers, a marvellous work requiring countless thousands of years . . . [Beyond the basin were] huge shining domes on the east, over the tops of which the grinding, wasting, molding glacier must have swept as the wind does today.

In August, while camped at the west end of Lake Tenaya, he

took a walk on the glacier-polished pavements along the north shore, and climbed the magnificent mountain rock at the east end of the lake, now shining in the late afternoon light. Almost every yard of its surface shows the scoring and polishing action of a great glacier that enveloped it and swept heavily over its summit . . . This majestic, ancient ice flood came from the eastward, as the scoring and crushing of the surface shows. Even below the waters of the lake the rock in some places is still grooved and polished; the lapping of the waves and their disintegrating action have not as yet obliterated even the superficial marks of glaciation. In climbing the steepest polished places I had to take off shoes and stockings. A fine region this for study of glacial action in mountain-making.

He called attention to another

knob . . . of burnished granite, perhaps a thousand feet high [which] probably owes its existence to the superior resistance it offered to the action of the overflowing ice-flood.

He was struck by the gap between Mount Hoffmann and Cathedral Peak,

which seems to be one of the channels of a broad ancient glacier that came from the mountains on the summit of the range. In crossing this divide the ice-river made an ascent of about five hundred feet from the Tuolumne meadows. This entire region must have been overswept by ice.

Camped three miles east of Lake Tenaya he theorized that,

Only in those cañons of the larger streams at the foot of declivities, where the down thrust of the glaciers was heaviest, do we find lakes of considerable size and depth.

The foregoing quotations are definite proof that in the summer of 1869, in the few brief days of his acquaintance with the Sierra, John Muir had already recognized the important part that ice had played in the sculpturing of the landscape.

Throughout this "profitable pilgrimage" he was striving in some way to "explain Yosemite grandeur . . . hopeful of some day knowing more, learning the meaning of these divine symbols crowded together on this wondrous page." Perched on North Dome he was "without definite hope of ever learning much" but still was "eager to offer self-denial and renunciation with eternal toil to learn any lesson in the divine manuscript."

It is quite clear that Muir had found the key to the problem that was uppermost in his mind and, in spite of the fact that he had only spent a few days in Yosemite Valley itself, was well on the road toward a clearer understanding of its origin than had previously been reached.

In a letter dated September 8th, 1871, to Mrs. Ezra S. Carr,8 he wrote:

You know that for the last three years I have been plodding making observations about this Valley and the high mountain region to the East of it, drifting broodingly about and taking in every natural lesson that I was fitted to absorb. In particular the great Valley has always kept a place in my mind. How did the Lord make it? What tools did He use? How did He apply them and when? I considered the sky above it and all of its opening cañons, and studied the forces that came in by every door that I saw standing open, but I could get no light. Then I said, "You are attempting what is not possible for you to accomplish. Yosemite is the end of a grand chapter. If you would learn to read it go commence at the beginning." Then I went about to the alphabet valleys of the summits, comparing cañon with cañon with all their varieties of rock structure and cleavage, and the comparative size ant slope of the glaciers and waters which they contained. Also the grand congregation of rock creations were present to me, and I studied their forms and sculpture. I soon had a key to every Yosemite rock and perpendicular and sloping wall. The grandeur of these forces and their glorious results overpower me, and inhabit my whole being. Waking or sleeping I have no rest. In dreams I read blurred sheets of glacial writing or follow lines of cleavage or struggle with the difficulties of some extraordinary rock form. Now it is clear that woe is me if I do not drown this tendency toward nervous prostration by constant labor in working up the details of this whole question.

Later in that year he wrote:9

Patient observation and constant brooding above the rocks, lying upon them for years as the ice did, is the way to arrive at the truths which are graven so lavishly upon them.

In a letter to Clinton L. Merriam, dated September 24th, 1871,10 he stated:

You know my views concerning the formation of Yosemite, that the great Valley itself, together with all of its various domes and sculptured walls, were produced and fashioned by the united labors of the grand combination of glaciers which flowed over and through it, their forces having been rigidly governed and directed by the peculiar physical structure of the granite of which this region is made, and, moreover, that all of the rocks and lakes, and meadows of the whole upper Merced basin owe their specific forms and carving to this same glacial agency.

He added11 that he believed in

the existence in the earlier ages of a Sierra Nevada ice of vast glaciers which flowed to the very foot of the range.

Already it is clear that all of the upper basins were fined with ice, so deep and universal that but few of the ridges were sufficiently high to separate it into individual glaciers. Vast mountains were flowed over, and rounded or moved away like boulders in a river.

Ice flowed into Yosemite by every one of its cañons, and at a comparatively recent period of its history, its north wall, with perhaps the single exception of the crest of Eagle Cliff, was covered with an unbroken stream of ice, the several glaciers having united before coming to the wall.

On November 16th, 1871,12 he wrote his mother that the valley was not "all exceptional creation," as had been claimed, but that

Yosemite is one of many, one chapter of a great mountain book written by the same pen of ice which the Lord long ago passed over every page of our great Sierra Nevadas. I know how Yosemite and and all the other valleys of these magnificent mountains were made and the next year or two of my life will be occupied chiefly in writing their history in a human book--a glorious subject, which God help me preach aright.

Professor Joseph LeConte, the distinguished geologist, was one of the first men with scientific training to recognize the accuracy of John Muir's observations. Meeting Muir in the valley in August of 1870, he persuaded him to go on to the Tuolumne Meadows with his party. Muir told him of his conviction that the glacier had done the excavating of the valley and of his finding residual glaciers on Mount Lyell and in the Merced group of peaks. Dr. LeConte's paper, "Some Ancient Glaciers of the Sierra," read in September, 1872, credited Muir for these discoveries.

Professor Louis Agassiz, upon reading what Muir had written on the Yosemite glaciers, said enthusiastically, "Here is the first man who has any adequate conception of glacial action . . . Muir is studying to greater purpose and with greater results than anyone else has done."

In the autumn of 1872 Muir again wrote Mrs. Carr13 that ice was practically the sole denuding agency, that

Yosemite and Hetch Hetchy are lake basins filled with [glacial material and that] The Yosemite ice in escaping from the Yosemite basin was compelled to flow upward a considerable height on both sides of the bottom walls of the Valley. The cañon below the Valley is very crooked and very narrow, and the Yosemite glacier flowed across all of its crooks and high above its walls without paying any compliance to it . . .

I am surprised to find that water has had so little to do with mountain structure here. Whitney says that there is no proof that glaciers ever flowed in this Valley, and yet its walls have not been eroded to the depth of an inch since the ice left it, and glacial action is glaringly apparent many miles below the Valley.

John Erasmus Lester, a visitor to Yosemite in 1872, met Muir and on his return to Rhode Island published and read before the Historical Society there a paper on Yosemite,14 in which he says:

There is and has been for two years past, living in the Valley, a gentleman of Scottish parentage, by name John Muir, who, Hugh Miller like is studying the rocks in and around the Valley. He told me that he was trying to read the great book spread out before him. He is by himself pursuing a course of geological studies, and is making careful drawings of the different parts of the gorge. No doubt he is more thoroughly acquainted with this valley than any one else. He has been far up the Sierras where glaciers are now in action, ploughing deep depressions in the mountains. He has made a critical examination of the superincumbent rocks, and already has much material upon which to form a correct theory.

Muir characterized Whitney's theory, as will be noted in his "Studies in the Sierra," in caustic language (see chapter ii).

Commenting on the part that water may have played in the formation of Sierra valleys, Muir called attention to the fact that in the postglacial epoch the channel of the upper Merced had not been deepened by the river more than three feet. He stated that the average angle which the slope of the Yosemite walls makes with the horizon, if carefully measures with a clinometer, was less than 50 degrees, and added that it was not possible for the bottom to drop out of a valley thus shaped. He emphasized the down-thrusting power of the five Yosemite tributary glaciers where as they entered the valley (see chapter iii) and also noted that after expending this power,

with which they were endowed by virtue of the declivity of their channels . . . the trunk flowed up out of the valley without yielding compliance to the crooked and comparatively small river canyon extending . . . from the foot of the main valley. In effecting its exit a considerable ascent was made, traces of which are to be seen in the upward slope of the worn, rounded extremities of the valley walls.

He concluded, after contemplating the evidences of the power exerted by the separate glaciers in Yosemite Valley, that, instead of being overwhelmed by the magnitude of the work accomplished, "we ask, Is this all? wondering that so mighty a concentration of energy did not find ye, grander expression." (See chapter iv.)

In answer to the query "What is the quantity of this degradation?' he emphasizes the crushing power of the currents of moving ice, which

slid over the highest domes as well as along the deepest cañons, wearing, breaking and degrading every portion of the surface, however resisting . . . given a sufficient length of time, and any thickness of rock, whether a foot or hundreds of thousands of feet will be removed. No student pretends to give an arithmetical expression as to the glacial epoch, though it is universally admitted that it extended through thousands or millions of years. Nevertheless, geologists are found who can neither give Nature time enough for her larger operations, or for the erosion of a mere cañon furrow without resorting to sensational cataclysms for the explanation of the phenomena.

The feeling engendered by John Muir's drastic criticism of Whitney's "bottom-dropping-out" theory of Yosemite's origin ran high. As already noted, Whitney's intense resentment undoubtedly explains his denial that there was any proof "that glaciers have ever occupied the Valley, or any portion of it," after having in his earlier geology given in some detail the unmistakable evidences of such glacial occupation of the valley. Of Muir's attribution of Yosemite's existence to glaciation he said that "a more absurd theory was never advanced . . ." He referred to Muir as a "sheepherder" and "guide." On the other hand Muir's intense feeling is expressed in many letters to his friends and later in his published articles, some of which have been noted above.

It is not surprising that Whitney and Muir felt as they did when all the surrounding circumstances are considered. Whitney was at the peak of his fame, recognized as one of the leading geologists in America, with an exceptional education acquired in America and Europe under the tutelage of outstanding scientists of the world. He had been called to California to undertake a geological survey of the state, which he himself, previous to his appointment by the legislature, had referred to as "the outstanding job of this character in America." After arriving in California he had been appointed by Governor Low to the "State Commission to manage Yosemite" and after Frederick Law Olmsted's resignation, had become its chairman. This made it necessary for him to visit the valley frequently. He wrote and published the first guidebooks of the valley and in these fully expounded his theory of its origin. Unquestionably, as chief geologist of a state survey of nation-wide interest, he had given the origin of Yosemite, already world-famous, his best considered thought and was aided by many able assistants. For his mature conclusions to be questioned and even belittled by a mere youth who had no college degree and no greater geological education than could be obtained at the comparatively new university in Wisconsin, was lese majeste. Whitney, proud and sensitive by nature, must have been galled beyond expression when, on his Yosemite visits and meetings with the Yosemite State Commission, of which he was chairman he was told, as must frequently have been the case, that this recently arrived and comparatively unknown stripling, was boldly questioning his carefully thought-out explanation. It savored of a David and Goliath contest. Muir's Scotch forthrightness and youth undoubtedly caused him to criticise Whitney's theory more severely than was politic. Muir also was doubtless irked by the fact that Whitney continued to insist on the correctness of his own theory even after its weaknesses had been exposed. Muir told me more than once that he regretted having gone as far as he did in criticising Whitney and that he should have been more deferential, for he really admired Whitney's ability and his geological survey work in California.15

Because of Whitney's doubts and diatribes, John Muir was naturally anxious to fortify his own views. He realized that in Alaska there were large glaciers performing today the same sort of work that had taken place in the Sierra in past geologic times. In his book, Travels in Alaska, published posthumously (1915), he tells of his various trips to the northwest coast and we find that these travels were in large part devoted to an intimate and detailed study of the Alaskan glaciers.16 He was a pioneer in these explorations, the first to map portions of this rugged coast, and named many of the hitherto unknown glaciers of Alaska. One of the largest, the Muir glacier, was named by others, in his honor.

Unlike most explorers, who are usually accompanied by a retinue of camp followers and vast quantities of equipage, Muir made these trips into the wild Alaskan fiords accompanied only by Indians and occasionally by the missionary, S. Hall Young. Traveling over the glaciers for days at a time he was invariably alone and, in fact, would have been handicapped had anyone accompanied him, for his skill as a climber and ability to travel light were unexcelled. His intense interest in the glacier problem is demonstrated by the large portion of his Alaska volume which is devoted to these expeditions. He saw with his own eyes "the huge ice tool" with its "mighty flood grinding against the granite walls with tremendous pressure." He found the "facts so fresh and telling and held up so vividly before us, every seeing observer, not to say geologist, must readily apprehend the earth-sculpturing, landscape-making action of flowing ice." In front of one of the glaciers he floundered through "grey mineral mud, a paste made of fine-ground mountain meal . . . swallowing us feet foremost with becoming glacial deliberation." He observed, "the streams that pour from them are busy night and day bringing in sand and mud and stones, at the rate of tons every minute." Muir continues:

Pushing on next day, I climbed to the top of the glacier by ice-steps and along its side to the grand cataract two miles wide where the whole majestic flood of the glacier pours like a mighty surging river down a steep declivity in its channel. After gazing a long time on the glorious show, I discovered a place beneath the edge of the cataract where it flows over a hard, resisting granite rib, into which I crawled and enjoyed the novel and instructive view of a glacier pouring over my head, showing not only its grinding, polishing action, but how it breaks off large angular boulder-masses--a most telling lesson in earth-sculpture, confirming many I had already learned in the glacier basins of the High Sierra of California.

In general all the rock walls as far as I saw them are more or less Yosemitic in form and color and streaked with cascades.

Again and again he was impressed with the massive granitic domes rocks

sculptured like those of Yosemite, magnificent valleys like the Yosemite.

That this whole system of fiords and channels was added to the domain of the sea by glacial action, is to my mind certain.

He found the

pre-glacial margin of the continent, eroded to varying depths below sea-level, and into which, of course, the ocean waters flowed as the ice was melted out of them.

Up over roping, mossy, bushy, burnished rock-waves we scrambled . . . [to] a fair view of the deep blue waters of the fiord stretching on and on along the feet of the most majestic Yosemite rocks we had yet seen.

He noted that the fiord was interrupted and

this novel interruption of the channel is a bar of exceedingly hard resisting granite, over which the great glacier that once occupied it swept, without degrading it to the general level and over which tidewaters now rush in and out with the violence of a mountain torrent.

He found many Yosemite-like "mansions of the icy North." Of one of them he says,

This is a Yosemite Valley in process of formation, the modeling and sculpture of the walls nearly completed and well planted, but no groves as yet or gardens or meadows on the raw and unfinished bottom. It is as if the explorer, in entering the Merced Yosemite, should find the walls nearly in their present condition, trees and flowers in the warm nooks and along the sunny portions of the moraine-covered brows, but the bottom of the valley still covered with water and beds of gravel and mud, and the grand glacier that formed it slowly receding but still filling the upper half of the valley.

He was profoundly impressed by the

extraordinary grandeur of [one] wild unfinished Yosemite. Domes swell against the sky in fine lines as lofty and as perfect in form as those of the California valley, and rock-fronts stand forward, as sheer and as nobly sculptured. No ice-work that I have ever seen surpasses this, either in magnitude of the features or effectiveness of composition.

Of one valley in particular he wrote:

This is in form and origin a typical Yosemite valley, though as yet its floor is covered with ice and water-ice above and beneath, a noble mansion in which to spend a winter and a summer! It is about ten miles long, and from three-quarters of a mile to one mile wide. It contains ten large falls and cascades, the finest one on the left side near the head . . .

The amount of timber on the walls is about the same as that on the Yosemite walls, but owing to greater moisture, there is more small vegetation,--bushes, ferns, mosses, grasses, etc.; though by far the greater portion of the area of the wall-surface is bare and shining with the polish it received when occupied by the glacier that formed the fiord.

The foregoing quotations from Travels in Alaska abundantly demonstrate that these Alaskan explorations gave him telling evidence in support of the theories which he had advanced and which are expounded in his "Studies in the Sierra.'' He saw the living glaciers of Alaska actually doing the same sort of rock-gouging and rock-plucking work that he was convinced the ancient glaciers of the Sierra had done in their work of fashioning the yosemities of California.

In 1893 he visited Switzerland and the fiords of Norway, searching for--and finding--further confirmation of his views.

In 1913 the interest in the Yosemite problem, both popular and in scientific circles, prompted the United States Geological Survey to undertake a comprehensive geologic investigation of the entire Yosemite region and neighboring High Sierra. To the glacial and geomorphic studies was assigned the distinguished topographer and geologist who had already made the superb topographic map of Yosemite Valley, the late François E. Matthes, an internationally recognized authority on glaciers. He was assisted by Frank C. Calkins, who investigated the rocks of the region. The results of many years of painstaking research by these geologists were published in 1930 as Professional Paper 160, entitled, Geologic History of the Yosemite Valley. This monumental work is generally recognized as a classic in geologic literature and one of the finest publications of the United States Geological Survey. The text, unique in that it is written largely in nontechnical language, in order that it may be understood by laymen and scientists alike, is supplemented by many fine illustrations, and by folded topographic and geologic maps.

In this monograph, as well as in various shorter publications, Matthes gives great credit to John Muir, "who first saw clearly that the glaciers themselves had done most of the excavating." However, Matthes's own studies indicated that "Muir . . . went too far in his claims for glacial erosion."

Matthes found that in the Yosemite region, as in most glaciated regions which similarly have been investigated in detail, the glacial record is very complex, indicating that the Glacial Period involved several distinct glaciations. In the interglacial stages between these glaciations, the Yosemite region was ice-free. Accordingly, Yosemite Valley was interpreted by Matthes as the joint product of stream erosion by the Merced River and of ice erosion by the glaciers of the several glacial stages. To answer the critical question "as to how much of the work was done by the streams and how much by the glaciers" Matthes employed the modern techniques of geomorphology (as explained fully in Professional Paper 160) and found that preglacial stream erosion formed a V-shaped canyon in the Yosemite granite, so that

at the lower end of the valley the glacial deepening measures only about 500 feet, but up the valley it increases gradually, reaching a maximum of about 1,500 feet near the head of the valley . . . lateral cutting has been a more important element in the transformation of the Yosemite chasm than downward cutting. At every point the widening accomplished exceeds the deepening. It is, in fact, mainly through lateral cutting that the narrow V canyon of preglacial time has been transformed into the broad U trough of today.

Matthes recognized that the glacier excavated "an elongated basin" which it "scooped out in the rock floor of the valley," thus creating a shallow "lake Yosemite" whose depth was increased by the terminal moraine dam below E1 Capitan. He did not know the depth of this lake basin, as no borings had ever been made to determine this fact, but estimated "a depth ranging from 100 to not less than 300 feet" for various parts of the valley, with the probability that "the basin was deepest . . . in the upper part of the valley, opposite Yosemite Village." He says, further, that

the existence of the rock basin is purely inferential . . . until a series of borings along the whole length of the valley shall afford the necessary facts,

and adds that such borings

would contribute much desired data regarding the still challenged eroding efficiency of glaciers . . .

As to the extent to which the ancient glaciers have remodeled and excavated the valley, nothing, perhaps would go further toward settling this vexed question than a series of direct measurements establishing beyond doubt the depth of former Lake Yosemite.17

The importance of rock structure, particularly jointing, in determining the facility with which the glaciers quarried and ground the rock surfaces over which they moved--a factor first recognized and expounded by Muir--was fully recognized by Matthes also, who developed the relationship in great detail, showing that jointing has played a major role in the control of the varied Sierra landforms.

In recent years another important chapter has been added to study of the depth of the bedrock floor and the rock basin below the existing surface floor of Yosemite Valley. Dr. John P. Buwalda, former head of the Division of Geology of the California Institute of Technology, investigated these problems by geophysical methods, through use of the Institute's seismic reflection equipment. Field work was done in 1934 and 1935, and subsequently the extensive mathematical calculations were made by a colleague, Dr. Beno Guttenberg. The procedures involved drilling holes in the valley to shallow depths, and the explosion of dynamite charges in these holes. The reflection returns of the resulting wave; were accurately timed, thus giving the depth to which the waves traveled before being reflected back from bedrock.

This study indicated that bedrock is deepest between the Government Administration Building and Camp Curry, where it is 1,800 to 2,000 feet below the present surface. Three miles downstream, opposite El Capitan, bedrock is 1,000 feet higher; and two and one-half miles farther downstream, at the lower end of the valley, bedrock is only 200 feet below the present surface. Upstream from Camp Curry, the depth decreases gradually and a short distance up on Tenaya Creek and on the Merced River near Happy Isles it steps up suddenly, the bedrock being actually exposed a mile or so still farther upstream.

This study, then, indicated that the glaciers scooped out a great spoon-shaped depression in the bedrock beneath what is now Yosemite Valley. The depression is 1,800 to 2,000 feet deep in the upper part of the valley, and 200 feet deep at its lower end. Where the depression is deepest; as in front of Camp Curry, bedrock is some 5,000 feet below Glacier Point--65 to 70 per cent of the total depth of the valley previously estimated at this point.18

Many geologists feel, as did Matthes, that the last word concerning the depth of bedrock below the floor of Yosemite must await a series of borings along the length of the valley. However, the geophysical studies, which have since been confirmed by an entirely independent series of tests, indicating as they do a maximum depth far greater than previously estimated, give new emphasis to John Muir's remarkable acumen in early discerning the great importance of glacial action in the formation of Yosemite and the other great canyons of the Sierra.

On the occasion of a program broadcast on April 17, 1938 in observance of the centennial of John Muir's birth, François Matthes paid this tribute to the pioneer student of the Yosemite:

To one thoroughly at home in the geologic problems of the Yosemite region it is now certain, upon reading Muir's letters and other writings, that he was more intimately familiar with the facts on the ground and was more nearly right in their interpretation, than any professional geologist of his time . . . Muir was probably as nearly right in his glacial theory of the Yosemite as any scientist in the early seventies could have been.19

Thus Muir's "Studies in the Sierra" still stand, after seventy-five years, as a splendid introduction to the fundamental workings of Nature that have created the Yosemite Valley as we know it today.

Glacier Writings of John Muir


Mountains of California. (Chapters on Glacier Meadows of the Sierra and Mountain Lakes of California.)

Travels in Alaska. (Much of this volume is devoted to the glaciers of Alaska.)

Articles in Books and Magazines

"Glaciers and Snow-banners." Contemporary biography of California's Representative Men. San Francisco. Bancroft, 1882. Vol. 2, pp. 104-112.

"Notes on the Pacific Coast Glaciers." (Harriman Alaska Expedition.) 1901, Vol. 1, pp. 119-135.

"The Glaciation of the Arctic and Sub-Arctic Regions Visited by the U. S. Steamer 'Corwin'" (1881). U. S. Senate documents, 48th Congress, 1st Session, 8:204, pp. 135-147.

"Peaks and Glaciers of the High Sierra." Picturesque California (1882).

"Studies in the Formation of Mountains in the Sierra Nevada, California." American Association for the Advancement of Science. (1824) Vol. 23, Part 2, pp. 49-64.

"Alaska'" American Geologist (1893), 2:287-299.

"Alaska Trip," Century, Aug. 1897, Vol. 54, pp. 513-526.

"Ancient Glaciers of the Sierra," Californian, Dec. 1880, Vol. 2, pp. 550-551.

"Discovery of Glacier Bay," Century, June 1895, Vol. 50, pp. 234-247.

"Living Glaciers of California," Overland, Dec. 1872, Vol. 9, pp. 547-549.

"Studies in the Sierra," Overland, 1874; Vol. 12, pp. 393-403, 489-500; Vol. 13, pp. 67-79, 174-184, 393-401, 530-540; Vol. 14, pp. 64-73.

"Mountain Sculpture," American Journal of Science, 1874, Vol. 7, pp. 515-516.


New York Tribune, "Yosemite Glaciers," Dec. 5, 1871.

San Francisco Bulletin, "Notes of a Naturalist, Alaska Glaciers," Sept. 23, 1879, Sept. 27, 1879; "Sum Dum Bay," Aug. 1880, Oct. 7, 1880; "An Alaska Yosemite," Oct. 16, 1880; "Among the Glaciers and Bergs of Sum Dum Bay," Oct. 23, 1880; "Taku Fiords and Glaciers," Nov. 13, 1880.

See also The Life and Letters of John Muir (2 Volumes, 1923-1924), by William Frederic Badè, and Son of the Wilderness, A Life of John Muir (1945), by Linnie Marsh Wolfe, for detailed accounts of this glacial controversy and the leading part that John Muir had in it.


1. John Muir, as a youth on his father's farm, easily excelled all the help in whatever he undertook. He kept his axes sharper and knew how to use them to great effect. He early demonstrated his ability as an inventor. His wooden clocks, barometer, thermometer, bed-tipping apparatus (to insure early rising), revolving desk (bringing each book before him at the appointed study hour), and his great success in inventing labor-saving devices in the factory where he was employed after leaving the University in Wisconsin, all attest to this. His grasp of geological problems and his intimate knowledge of botany are proof of the fact that both Emerson and Agassiz were justified in urging him to lecture at Harvard on these subjects, an invitation which had little appeal to such a lover of outdoor freedom. His explorations in Alaska and other parts of the world made him eligible to be called an explorer. His great success as a grower of grapes and fruit, when he netted more than $10,000 a year for ten consecutive years and then decided that he had laid away money enough for all worldly purposes, illustrates the success that he made of everything he put his hand to. But above an else he excelled as a writer and teacher of the gospel of the outdoors that he loved so well. Few have approached him in his rare ability to interpret nature and translate her moods in language that has such universal appeal.

The events in his full life are so ably narrated in Son of the Wilderness, the Life of John Muir, by Linnie Marsh Wolfe (1945), that the reader is referred for all such incidents to this Pulitzer Prize biography. Also see Dr. William Frederic Badè's Life and Letters of John Muir (1923), and John Muir's Story of My Boyhood and Youth (1913), as well as Reader's Digest, September, 1949.

2. These are set forth and discussed in Geologic History of Yosemite Valley (1930), by François E. Matthes, U. S. Geological Survey Professional Paper 160 (pp. 4-6, 94-95). Also see The Life and Letters of John Muir (1923), by William Frederic Badè, chapter ix, "Persons and Problems" (pp. 275-278, 282-287, 308-309, 352-353, 356-359); and Son of the Wilderness (pp. 130-135, 186-187).

E. C. Andrews, the noted geologist of Australia, in 1910 wrote a monograph entitled "An Excursion to the Yosemite" (Roy. Soc. New South Wales Journal, vol. 44, pp. 262-315), in which he emphasizes the importance of "glacial stairways" in the process of glacial erosion. Later, in a letter to me he stated that he had for the first time read Muir's "Studies in the Sierra," just being published in the Sierra Club Bulletin, and added that "John Muir's note on glacial action is very fine indeed. In Muir you had a man in America long ago who explained the action of ice rivers ...."

Andrew C. Lawson, a long-time member of the Sierra Club, and former head of the Department of Geology of the University of California, has expressed his views on this subject in an article entitled "Geology of Yosemite National Park," which appeared in Anson Hall's Handbook of Yosemite National Park (1921, pp. 99-122).

3. An article by John Muir entitled "Yosemite Glaciers" appeared in the New York Tribune, December 5, 1871. In the December 1872 Overland Monthly appeared another article by him entitled "Living Glaciers of California." The fun and detailed presentation of his theory followed in 1874 and 1875 in the series of seven articles "Studies in the Sierra."

4. The demand for this publication was so great that the original edition of 1930 was exhausted, and a reprint became necessary, first in May, 1939, and again in May, 1946. It may still be purchased from the Superintendent of Public Documents, Government Printing Office, Washington, D.C., for $3.25.

I have a copy of this paper which contains the following inscription:

"To Wm. E. Colby, who, as Secretary of the Sierra Club, took the first steps toward bringing about the reinvestigation of the Yosemite Valley of which the results are here set forth.--François E. Matthes."

In recognition of Matthes' splendid work the Sierra Club elected him an Honorary Vice-President. Matthes died in June, 1948, shortly after retirement from the Geological Survey. It is hoped that his remaining Sierra studies will be brought to completion and published posthumously.

5. Josiah Dwight Whitney, 1819-1896, a distinguished American geologist who, prior to his becoming the Chief Geologist of the California Geological Survey, was connected with official geological surveys in the states of New Hampshire, Wisconsin, and Illinois. He headed the California Survey from 1860 to 1874 and not only prepared a large volume on geology of California published by the state in 1865, but also wrote and published various guide books to Yosemite Valley, 1869-1874. He was Professor of Geology at Harvard University, 1865-1896. Whitney doubtless aided in the passage of the Act of Congress which, on June 30, 1864, granted to the State of California "the cleft or gorge . . . in the Sierra Nevada Mountains, known as Yosemite Valley"--for this language reflects his theory of the valley's origin. Whitney refers to the Yosemite Valley as "the Gosh a'Mighty" in a letter to his brother dated June 19, 1861. (Brewster's Life and Letters, Josiah Dwight Whitney (1909), p. 202.)

6. It is extraordinary that a man of Whitney's ability should have failed to be impressed by the evidences of glacial action in the Sierra, which he himself had seen and noted. In a letter, dated July 10, 1863, to his friend Professor G. J. Brush, he writes of the view from Mount Dana and of the Tuolumne Meadows region as follows:

. . . we are in the midst of what was once a great glacier region (italics Whitney's) the valleys all about being most superbly polished and grooved by glaciers, which once existed here on a stupendous scale, having a thickness in the Tuolumne Valley, of a thousand feet, and having left splendid moraines--medial, lateral, and terminal. The beauty of the polish on the rocks, covering hundreds of square miles of surface, is something which must be seen to be appreciated. [Life and Letters, Josiah Dwight Whitney, pp. 230-231.]

Clarence King, leader of early geological surveys in the western United States and later a director of the U. S. Geological Survey, was, apparently, more interested in glacial action than any of his collaborators, as shown by the fact that Whitney credits him with most of the reported data on the subject contained in the California Survey publications. Had he not been under the dominating influence of a scientist as positive as Whitney, he might have originated the "glacial theory" of the origin of Yosemite which some have erroneously credited to him. That he did not endorse that theory, in spite of his many observations indicating that the ancient glaciers had been very widely distributed in the High Sierra and had occupied Yosemite Valley, is demonstrated by his complete acceptance of Whitney's theory in his "Mountaineering in the Sierra Nevada."

7. My First Summer in the Sierra, by John Muir (1911).

8. The Life and Letters of John Muir, vol. i, pp. 293-95.

9. Ibid., p. 300.

10. Ibid., p. 303.

11. Ibid., pp. 307-308.

12. Ibid., pp.314-315.

13. Ibid., pp. 354-356.

14. Ibid., p. 360.

15. See Son of the Wilderness, pp. 130-133. Professor Whitney was made an honorary member of the Sierra Club in December, 1892. Though John Muir was not present at that meeting he doubtless had been consulted and had given his approval to this action. If my memory serves me aright (the official minutes having been destroyed in the 1906 San Francisco Fire) at John Muir's suggestion, Whitney's sister was substituted in her brother's place to receive Sierra Club publications after his death in 1896.

16. Tarr and Martin in Alaskan Glacier Studies (1914), sponsored by the National Geographic Society, credit Muir as the pioneer in publishing accounts of Alaskan glacier studies. (Muir's first trip to Alaska was in 1879.) In this excellent presentation of their detailed studies, the authors confirm many of the conclusions earlier reached by Muir as to the tremendous erosive power of the Alaskan glaciers. See pp. 219, 224, 226, 228-230, 341, 357-358, 367-368.

17. "Little Studies in the Yosemite Valley," by François E. Matthes, Sierra Club Bulletin, 9:15.

18. I am indebted to Dr. Buwalda for permission to use these data, which are taken from his illuminating article, "Form and Depth of the Bedrock Trough of Yosemite Valley," Yosemite Nature Notes, 20 (October, 1941): 89-93.

Dr. Buwalda writes as of August 10, 1949:

"Many of the 85 points in the Valley at which we determined the depth of the fill have been re-shot subsequently by another geophysical crew with entirely different equipment and the results check."

If we accept Dr. Buwalda's findings, now corroborated by entirely independent tests, the Yosemite glacier excavated upwards of a cubic mile of granite rock and transported it out of this spoon-shaped lake depression. The removal of this material cannot be attributed to water erosion for it was all originally situated in place back of and below the elevation of the now existing downstream lip of the lake. This recently discovered evidence of the enormous excavating power of the glacier lends confirmation to Muir's main thesis that glaciers were largely instrumental in carving out much of what is now the Valley void, observable to an visitors. Geologists will still differ about the relative amount of this excavation and erosion that was done by water and later by ice, but from now on a heavier burden win rest on the advocates of water erosion.

19. "John Muir and the Glacial Theory of Yosemite," by François E. Matthes, Sierra Club Bulletin, 23:2 (April, 1938), pp. 9-10.

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