Geological Survey Professional Paper 504—A Glacial Reconnaissance of Sequoia National Park California

Sequoia National Park (fig. 1) comprises an irregular tract 604 square miles in extent on the west slope of the Sierra Nevada between lat. 36°18' N. and 36°42' N. and between long. 118°14' W. and 119°00' W. (pl. 1). It embraces chiefly the scenic upper part of the range, including the main crestline, and in that respect it is situated much like Kings Canyon National Park, which adjoins it directly on the north, and Yosemite National Park, which lies a hundred miles farther to the northwest (figs. 2, 3). But Sequoia National Park has the distinction of including the culminating stretch of the crestline, bearing Mount Whitney (14,495 ft) and six more of the eleven 14,000-foot peaks of the Sierra Nevada; the park has the additional distinction of being traversed from north to south by a secondary crest that is but little lower than the main crest—the Great Western Divide. Noteworthy also is the fact that Sequoia National Park has the greatest range of altitude of any national park or national monument in the United States, south of Alaska. Its lowest point, in the canyon of the Kaweah River near the entrance below Ash Mountain Park Headquarters, is only about 1,400 feet above sea level. Thence to the top of Mount Whitney, therefore, the change in altitude amounts, in round numbers, to 13,100 feet.

FIGURE 1.—Index map showing location of Sequoia National Park. (click on image for a PDF version)

FIGURE 2.—Idealized section across the Sierra Nevada representing the simple "textbook conception" of its tilted-block structure. That conception fits approximately the facts as they are known in the central part of the range, in the latitude of Yosemite Valley. Both northward and southward, however, the structure becomes more complex.

FIGURE 3.—Idealized section across the Sierra Nevada in the latitude of Sequoia National Park. Step faults exist at the western margin of the range as well as at the eastern margin, and the west slope consequently breaks off rather abruptly in the foothills belt. Some distance from the foothills, the tops of peaks on the down-faulted buried fault block emerge as isolated rocky hills above the sediments that fill the San Joaquin Valley. From Matthes (1950a, p. 3).

All of the three national parks in the Sierra Nevada include parts of that scenic upper region near the main crestline which Californians aptly call the "High Sierra." This region is a mountain land of truly alpine character, whose jagged snow-flecked peaks rise high above the timberline and whose strongly glaciated valleys are dotted with hundreds of picturesque lakes and lakelets. Of this alpine upper country, Sequoia National Park embraces the southernmost part. Its southern boundary, indeed, coincides approximately with the line where the High Sierra comes to an end; thence southward the range assumes a more subdued aspect, none of its summits rising above timberline.

In one other respect Sequoia National Park differs markedly from its two sister parks. Both Yosemite and Kings Canyon National Parks are traversed by southwestward-trending rivers—that is, by rivers that flow directly down the west slope of the range, roughly parallel to the rank and file of the master streams. The drainage net of Sequoia National Park, on the other hand, is complicated by the secondary mountain crest previously mentioned, the Great Western Divide. To the west of that divide is the drainage basin of the Kaweah River, the southernmost of the great series of southwestward-flowing master streams. To the east of the divide, on the other hand, is the headwaters basin of the Kern River; this river flows directly southward in a nearly straight line, parallel to the main crestline, and maintains that unusual course for 75 miles before turning in a southwesterly direction toward the Great Valley of California. The Kern River, moreover, heads against the South Fork of the Kings River, to the north, and as a consequence the Kaweah River does not reach up to the main crestline.

The Great Western Divide is far more than a mere ridge or crest; it is a mountain range in itself (fig. 4). Surmounted by a row of sharp-profiled peaks from 11,000 to more than 13,000 feet in altitude, and unbroken by any profound gaps,¹ it constitutes in effect a formidable barrier that trends from north to south across the park and divides it into two approximately even but very dissimilar halves. The divide stands 2,000 to 3,000 feet above the valleys at its eastern base and 4,000 to 6,000 feet above the canyons at its western base. Viewed from points in the western half of the park—as from Moro Rock, on the edge of the Giant Forest—the Great Western Divide has the appearance of a spectacular alpine range, and as a consequence it is commonly mistaken by sightseers for the main crest of the Sierra Nevada. The main crest actually lies behind the Great Divide, completely hidden from view.

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¹The only trail-passes over the Great Western Divide are Kaweah Gap (10,700 ft.), Black Rock Pass (11,500 ft.), Franklin Pass (11,300 ft.), Shotgun Pass (11,300 ft.), and Coyote Pass (10,034 ft.).

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FIGURE 4.—View eastward toward headwaters of Middle Fork, Kaweah River. The snow-clad peaks on the skyline are on the Great Western Divide. In the left foreground is Moro Rock, an imperfect dome that owes its rounded form to long-continued exfoliation of the massive granite. At the lower right is the canyon of the Middle Fork. Aerial photograph by Frank Webb.

Finally, a word about the country between Sequoia National Park and the western foothills of the Sierra Nevada. In an airline, that country measures 12 to 15 miles in width. From the point where the Kaweah River leaves the park to the embayment in which it debouches upon the plain of the San Joaquin Valley, the airline distance is only 11 miles. Looking down the Kaweah River canyon from the top of Alta Peak or from the rim of the Giant Forest platform, one is impressed by the multiplicity of rugged ranges and spurs advancing toward the canyon from either side, one behind another, at successively lower heights, parallel to the border of the distant plain. The name that has been given to one of the viewpoints on the Generals Highway—Eleven Range Point—well expresses the effect which the landscape makes upon the spectator.

Between those successive ranges and ridges are deep-cut canyons and gulches tributary to the Kaweah. The majority of these canyons trend at right angles to the southwesterly course of the master stream, but an inspection of the topographic maps shows that this trend is by no means universal and that, taken as a whole, the drainage pattern is extremely varied and irregular. Nor is the alinement of the ridges with the foot of the range as parallel and as persistent as their appearance in the distant view would seem to indicate. The map shows, furthermore, that not all are sharp crested; a considerable proportion have broad undulating summit areas.

There is no complete gradation of summit levels all the way down to the San Joaquin Valley. That fact is evident at once to the traveler who approaches the mountain range from the west, by way of either Lemon Cove or Woodlake. Even the first outlying hills which he passes rise abruptly 500 to 1,000 feet above the level of the plain, and the first continuous ridges of the mountain mass rise 1,500 to 2,000 feet above the plain. These ridges form an irregular, steep mountain front that resembles an escarpment.

KAWEAH BASIN

The western half of the park is profoundly dissected by the converging branch canyons of the Kaweah River system (fig. 5). Though none of its peaks rise to great altitude, it is an extremely rugged piece of country, difficult to traverse save on manmade roads or trails. The main canyon of the Kaweah River at Ash Mountain Park Headquarters is 3,000 to more than 4,000 feet deep. Ash Peak (5,621 ft), on the northwest side, stands 4,100 feet above the river, and Milk Ranch Peak (6,305 ft), on the southeast side, 4,800 feet. The canyons of the North, Middle, East, and South Forks are even deeper. Paradise Peak (9,370 ft) stands 5,400 feet above the East Fork and 6,400 feet above the Middle Fork. Homers Nose (9,005 ft) stands 5,200 feet above Clough Cave, on the South Fork, and 5,500 feet above the East Fork. The Castle Rocks (9,150 ft) rise 6,150 feet above the Middle Fork, and Alta Peak (11,211 ft) rises 6,910 feet above it.

FIGURE 5.—Panoramic view from Alta Peak of the broad west slope of the Sierra Nevada. The Kaweah River canyon, left of center, is one of the many deep trenches cut by westward-flowing rivers. The foothills are 27 miles away. Beyond them is the level San Joaquin Valley, deeply filled with silt, sand, and gravel washed down from the bordering ranges. On the horizon, barely discernible because of the south haze, are the Coast Ranges, more than a hundred miles distant. Photograph by L. Moe.

Some parts of the Kaweah Basin, however, are not deeply dissected by canyons but consist of undulating plateaulike uplands traversed by shallow valleys. Of these upland areas—which are clearly surfaces recording successive stages in the erosional history and rise of the Sierra Nevada (Matthes, 1930, 1933, 1937, 1950a, 1960)—the most extensive is in the headwaters of the Marble Fork. The platform on which the Giant Forest stands (figs. 6, 7), at altitudes ranging from 6,500 to 7,000 feet, is a characteristic part of this upland; Lodgepole and Tokopah Valleys, in the middle course of the Marble Fork, also form part of it. High above the Giant Forest, however, on the summit of Panther Peak (9,044 ft) is another much smaller platform or flat; 2,000 feet above that, again, is a third flat on the top of Alta Peak (11,211 ft). Thus the landscape appears to rise by successive stories, each being marked by a level of gently undulating surface that contrasts with the steep mountain slopes between.

FIGURE 6.—View up unglaciated lower part of Kaweah River canyon toward the platform on which the Giant Forest stands. At the right, Moro Rock. Moro Rock owes its prominence in the landscape to the fact that it is composed of massive granite. The platform is also held up mainly by massive granite, but the mountain slopes below have been eroded from normally jointed rocks, partly granitic, partly metamorphic.

FIGURE 7.—View westward from Moro Rock along the cliffs bordering the platform on which the Giant Forest stands. Part of the Giant Forest is seen at the right. The cliffs are of sparsely jointed granite that is exfoliating very slowly and rather irregularly. Similar massive granite outcrops elsewhere on the platform indicate that the whole platform is made up largely of this durable material; it is no doubt to this circumstance that the platform, a remnant of an ancient erosion surface, owes its preservation.

UPPER KERN BASIN

The upper Kern Basin, which forms approximately the eastern half of the park, contrasts strikingly with the Kaweah Basin, both in general configuration and in arrangement of drainage lines (pl. 2). Instead of being intricately dissected by a maze of branching canyons and gulches, the Kern Basin has a broadly open, spacious aspect. This spaciousness is due not merely to the fact that the neighboring mountain ranges—the Great Western Divide on the west and the main crest of the Sierra Nevada on the east—stand 13 to 18 miles apart but also to the presence of extensive terracelike benchlands that flank the central canyon and give the basin what appears, at least from a distance, to be a broad and nearly level floor. These benchlands, like those in the Kaweah Basin, are ancient erosion surfaces, better preserved here, perhaps, than in any other section of the Sierra Nevada. From these benchlands and from the even older erosion surfaces recognizable in the tabular summits of certain of the peaks may be read the record of the rise of the Sierra Nevada. Their characteristics and significance were set forth in the pioneer study of Lawson (1904) and in the later studies of Webb (1946) and of the author (Matthes, 1930, 1933, 1937, 1950a, 1960). (See fig. 8.)

FIGURE 8.—Simplified profile across the Upper Kern Basin, showing remnants of four ancient landscapes (erosion surfaces) at different levels above the Kern Canyon. The gently sloping summit of Mount Langley, like that of Mount Whitney, is a remnant of a hill in the lowland (Whitney erosion surface) that existed before the first major uplift of the Sierra region took place. The rounding summit of Cirque Peak is representative of a more mountainous landscape (Cirque Peak erosion surface) formed during the long interval between the second uplift and the third. The Boreal Plateau is a large remnant of an undulating landscape (Boreal Plateau erosion surface) that was also produced during the interval between the second uplift and the third. Chagoopa Plateau and the corresponding benches on the east side of Kern Canyon are remnants of a bread valley (Chagoopa erosion surface) that was evolved during the interval between the third uplift and the fourth. The Kern Canyon has been cut since the fourth and latest uplift, which took place at about the beginning of the glacial epoch. It is a product of alternate stream erosion and glacial erosion and is still in the process of being cut deeper. From Matthes (1950a, p. 12, 13). Vertical exaggeration X 2.

At its head the Kern Basin is encircled by the Kings-Kern Divide and the Great Western Divide, which form one continuous jagged mountain range. The Great Western Divide is strongly bowed toward the west, but the main crest of the range is locally bowed towards the east; the basin as a whole is therefore spoon shaped in outline. Even more apt, in view of the simple drainage pattern, is its likeness to a foliage leaf, as suggested by Lawson (1904). The straight Kern River traverses the basin axially like the midrib of the leaf, and the tributary streams branch from it at intervals, like veins. This simple pattern, it should be observed, is limited strictly to the upper basin, which lies within the limits of the park. Farther south, the drainage net becomes more complex, some of the tributary streams running parallel to the southflowing Kern River for considerable distances. Examples are the Little Kern River, which flows southward for a distance of 16 miles between the southern portion of the Great Western Divide and the Hockett Meadows Plateau, and the South Fork of the Kern, which pursues an irregular but, in the main, southerly course for some 50 miles (air-line distance) through the eastern part of the Sierra Nevada before turning southwestward to join the master stream.

The upper Kern Basin, further, is much less deeply trenched than is the Kaweah Basin. Throughout most of its length the Kern Canyon is only 2,000 to 2,500 feet deep. Whereas the Kaweah River has cut its canyon down to an altitude of 1,400 feet at the point where it leaves the park, the Kern River has an altitude of 6,400 feet where it crosses the southern park boundary. It follows that the upper Kern Basin, as a whole, is a region of relatively great altitude. The broad benchlands flanking the Kern Canyon range from an altitude of about 8,000 feet at the southern boundary of the park to more than 11,000 feet at the head of the basin.

The benchlands vary greatly in width—from a few yards to several miles—owing to the presence of bold spurs and mountain groups that project here and there from the enclosing ranges. At intervals, moreover, these benchlands are cut across by tributary canyons: yet, as is evident at once in any comprehensive view, they are remarkably persistent throughout the length of the basin. Though by no means level—from the flanking mountain ranges they slope down to brinks of the Kern Canyon at rates of 500 feet and more to the mile, and, in addition, are interrupted by low ridges and vales—the benchlands together form a distinct story in the landscape that contrasts with the towering mountains above and the steep-sided canyon below. They form a story not unlike that of the Giant Forest platform or of the Hockett Meadows Plateau in the Kaweah Basin but far more extensive and more clean-cut than either of these.

Particularly broad and typically developed is that section of benchland which is known as the Chagoopa Plateau (fig. 9). It is on the west side of the Kern Canyon immediately above the junction of the great side canyon called the Big Arroyo. This plateau extends 3 miles back from the canyon rim and in that distance rises from about 8,500 feet to more than 10,500 feet in altitude. Immediately above it loom Mount Kaweah (13,816 ft) and the great Red Spur (13,186 ft) which, together with the Red Kaweah (13,754 ft) and the Black Kaweah (13,752 ft), form one of the most imposing mountain groups that are attached to the Great Western Divide. To the tourist public the Chagoopa Plateau is well known, for it is traversed by the High Sierra Trail, the main horse trail leading from the Giant Forest to Mount Whitney.

FIGURE 9.—View westward across the Kern Canyon to the Chagoopa Plateau; Kaweah Peaks Ridge in the background. The timbered plateau on both sides of the canyon is a remnant of an erosion surface; that forming the Chagoopa Plateau is particularly striking. In the foreground, at the lower right, is a small hanging valley.

The Chagoopa Plateau and the benchlands of corresponding altitude on the opposite side of the Kern Canyon are not, however, the only story in the landscape of the upper Kern Basin. As in the Kaweah Basin, so here there are several plateaulike flats or benches at different levels one above another (pl. 2). A prominent example is the Boreal Plateau, a gently undulating upland bench averaging more than 11,000 feet in altitude and stretching for a distance of 7 miles along the southeastern boundary of the park. Above it, again, is the broadly convex summit of Cirque Peak, which ranges from 12,200 to 12,863 feet in altitude (pl. 2). And high above that peak rises the summit platform of Mount Langley, which ranges from 13,800 to 14,042 feet in altitude. Even Mount Whitney, the highest peak of the Sierra Nevada, has a broad, gently sloping summit platform (figs. 8, 10). The platform, which is closely analogous to the one on Mount Langley, rises from 14,000 to 14,495 feet in altitude. Indeed, so very similar in general form are the two peaks that in 1871 Clarence King (1872), one of the early explorers of the Sierra Nevada, mistook Mount Langley for Mount Whitney and climbed it thinking that he was ascending the culminating peak of the range.

FIGURE 10.—View northwestward from the main Sierra crest across the upper Kern Basin to the Great Western Divide. An ancient erosion surface is preserved on the summits of Mount Whitney, in the foreground, and Mount Young, the adjacent peak. Other, younger erosion surfaces form the plateaus bordering the Kern Canyon. Numerous cirques scallop the main Sierra crest and the Great Western Divide. Aerial photograph by Roy Curtis.

It is not to be inferred from the foregoing that flat plateaulike summits are the rule or even are prevalent on the main crest of the Sierra Nevada. The summits of Mount Whitney and Mount Langley, and the lower one on Cirque Peak, are the only ones on that part of the main crest that flanks the Kern Basin. Farther north in the range, a few flat summits occur at long intervals—for example, on Mount Darwin (13,841 ft and 13,701 ft) and on Mount Wallace (13,328 ft) at the head of the upper San Joaquin Basin (Matthes, 1960, p. 38, 41) and on a continuous platform (12,500 to 13,000 ft) 3-1/2 miles long in Yosemite National Park (Matthes, 1937, p. 8-9)—but most of the peaks are sharp profiled, as are those on the Great Western Divide. Only one of the peaks on the Great Western Divide, Table Mountain (13,646 ft), has a clean-cut tabular summit platform (fig. 11), although a few others have ill-defined sloping summit areas.

FIGURE 11.—View southeastward toward cirques on the Great Western Divide, which forms part of the boundary between Sequoia and Kings Canyon National Parks. Table Mountain, the flat-topped peak to the right of center, is one of the dominating summits of the divide. Aerial photograph by Frank Webb.

The Great Western Divide and the main crest of the range are much alike in general character, indeed, are much like the majority of the serrate mountain crests that traverse the High Sierra for more than a hundred miles northward. Each consists essentially of a single chain of lofty angular peaks connected with each other by narrow, sharp crested, often splintered or pinnacled ridges (fig. 12). Their sprawling spurs likewise are for the most part narrow and sharp crested, whereas the intermediate canyons as a rule are broadly U-shaped and head in steep-walled amphitheaterlike bowls. These ranges accordingly possess predominantly attenuated, sharply pointed forms and in a sense are "skeleton ranges." Some parts of the main crest of the range—in the vicinity of Mount Barnard, Mount Whitney, and Mount Langley—however, depart somewhat from that general character, the forms at these places being more fullbodied, the summits tabular or gently sloping, and the spurs broad enough to have rounding contours.

FIGURE 12.—View northward from Mount Whitney toward Mount Russell (center). Here, as a result of the headward quarrying of the glaciers that formerly occupied the opposing cirques, there remains of the former main crest of the range only the rock wall that connects the two peaks. The abundance of loose rock waste shows that the granite here breaks up readily—more readily than avalanches, running water, and gravity can remove the debris. The destructive action of alternating frost and thaw doubtless is promoted by the numerous vertical joint fractures. Photograph by Kenneth Flewelling.

In both ranges, however, the U-shaped canyons and the capacious amphitheaters seem wholly out of proportion to the small volume of the streamlets that descend through them. These streamlets in many places find their way among the knolls and bumps of the rock floors without definitely incised channels—here cascading over rock steps that as yet show no signs of stream erosion, and there meandering through grassy meadows or losing themselves in gemlike lakelets (fig. 13). These features stand out all the more vividly in the landscape because the canyons and amphitheaters lie mostly, or in some places entirely, above the timberline, in the lower fringes of what is properly termed the "Alpine zone."

FIGURE 13.—One of the many lakelets occupying glacially quarried rock basins in the upper Kern Basin, above the junction of Milestone Creek. The granite at the sides, being only sparsely fractured, was not readily quarried away and consequently shows the effects of abrasion.

From the lofty summits on the main crest of the Sierra Nevada, one looks down its precipitous east front into Owens Valley below. Particularly impressive is the view from Mount Whitney, not merely because of the great height of that peak above the valley—10,800 feet, or more than 2 miles—but because the spectator stands at the immediate, sharp-cut brink of a precipice that falls away sheer 1,500 feet beneath his feet. So breathtaking is the scene that the entire mountain front seems to drop off sheer like a wall. Yet, as is clearly shown on the accurately constructed topographic map, the foot of the range is fully 5 miles out from the peak in horizontal distance.

Even more incredible does it seem that the base of the great escarpment is itself fully 3,000 feet above the valley floor on which stands the town of Lone Pine. What appears to be a level plain at the foot of the range is in reality a slope that descends 2,000 feet in a distance of 5 miles. And what appear to be insignificant hillocks at the farther limits of the slope are the fantastically shaped crags and pinnacles of the Alabama Hills, a picturesque miniature range that looms 1,000 to 1,400 feet above Lone Pine and has furnished the weird setting for many a moving picture allegedly filmed in India within sight of the great Himalayas—this mountain system being adequately represented in the background by the Sierra Nevada.

Over the broad level floor of Owens Valley, one can readily trace the serpentine course of the Owens River, conspicuous by reason of its fringe of deep-green bushes. Beyond the river stretches the long-drawn somber-hued Inyo Range, which forms the east wall of the valley, parallel to the Sierra Nevada. From altitudes of 8,000 and 9,000 feet at its southern end, the Inyo Range rises irregularly to altitudes of 13,000 and even 14,000 feet in its northern part which, because of its contrasting light-colored rocks, is known as the White Mountains.

Southeastward, diagonally across Owens Valley and over gleaming Owens Lake in its bosom, are the relatively low Coso Mountains and several more distant mountain groups, and, more distant still, the lofty Panamint Range, behind which, deeply ensconced, lies Death Valley.

The stupendous panorama from the summit of Mount Whitney is in truth second only to the Big Trees among the park's natural exhibits as an inspiration for wonder and thought.

KERN CANYON

The great Kern Canyon extends due south through Sequoia National Park and divides that part of the Kern River basin lying within the park into two nearly equal parts.

From a geomorphological point of view, the head of the canyon may be regarded as being at Junction Meadow, where three branch canyons unite (fig. 14). The central branch canyon, though alined with the Kern Canyon, is distinctly subordinate to it in size and is separated from it by a great canyon step; this branch canyon is therefore of the rank of a tributary to the main canyon rather than a part of it.

FIGURE 14.—View northwestward from Mount Guyot. The Kern Canyon extends from the center of the picture toward the lower left; three branch canyons unite at its head. Photograph by Carl F. J. Overhage.

In its 17-mile stretch from Junction Meadow to the vicinity of Coyote Creek, where it leaves the park, Kern Canyon follows a nearly straight course that doubtless reflects structural control, as suggested by Lawson (1904) and further analyzed by Webb (1936, 1946), this control being a fault or zone of faulting. The canyon is a typical glacial U-shaped trough (figs. 15, 16). Indeed, it is no overstatement to say that few glacial canyons, either in the Sierra Nevada or elsewhere, possess so nearly perfect a U-shaped form due to glacial excavation and maintained for so long a distance. The principal reason for its regularity is that the trough is sunk along the axis of a geomorphically postmature valley of great breadth and consequently has sharply defined rims, or shoulders, formed by the intersection of its precipitous walls with gently sloping uplands at both sides. (These shoulders, it is true, are broken at intervals by side canyons, and in other places on the uplands they make way for hills of moderate height.)

FIGURE 15.—View southward down the Kern Canyon from a point on the west rim near mouth of Rattlesnake Creek. The pronounced U-shaped form of the canyon has been evolved by glacial erosion from a narrow V-shaped trench. The walls, once smooth, are now furrowed by gullies; talus slopes at their base produce the curves of a new U-shaped form superimposed on the glacially eroded one. Photograph by L. Moe.

FIGURE 16.—View southward down the Kern Canyon from a point below the rim north of Wallace Creek. The canyon is not straight throughout, although its course is probably determined by a fault or by several closely spaced parallel faults. Photograph by Kenneth Flewelling.

In the section within Sequoia National Park, the Kern Canyon is deepest at its head and becomes progressively more shallow southward. At Junction Meadow it is 2,500 to 2,600 feet deep; at the mouth of the Big Arroyo, 10 miles farther downstream, it is 2,000 feet deep, and opposite the rocky knob 14 miles below Junction Meadow, it is only 1,600 feet deep.

These depths, it may be objected, are measured from the rims of the flanking uplands, and those uplands are not a mathematical plane, but parts of an undulating, locally even hilly erosion surface. Allowance therefore should be made for the inequalities in that surface. To obviate errors from this source, the three measurements cited above were made at localities where the flanking uplands slope gently toward the rims and most probably represent the marginal parts of the ancient valley in which the U-shaped trough is sunk. Another source of error cannot be avoided. At Junction Meadow the U-shaped trough is 1-3/4 miles wide from rim to rim, whereas it narrows to about 1 mile in its lower half; the depth indicated at Junction Meadow is therefore likely to be excessive, for the walls of the U-shaped trough there cut higher into the sloping up lands than they do in the narrow part of the canyon. Careful examination of the topographic map, however, shows that the error thus introduced probably does not amount to more than a few hundred feet. That being admitted, there can be no doubt that the progressive southward shallowing of the U-shaped trough is due primarily to the fact that its floor has a decidedly lower grade than does the bordering upland surface.

The grade of the canyon floor is reliably represented on the topographic map, for a line of spirit levels was run by the Geological Survey up the bottom of the Kern Canyon from Grasshopper Meadow (4-1/2 miles south of the park boundary) to Junction Meadow. The first stretch of 7 miles above Coyote Creek—that is, up to the mouth of the Big Arroyo—has a very low grade. This is the stretch that is aggraded behind a morainal dam. The altitude of the bench mark at Coyote Creek is 6,458 feet; the altitude of the bench mark at the mouth of the Big Arroyo is 6,664 feet. The rise in that 7-mile stretch, therefore, is only 206 feet, or, on an average, 29 feet per mile. From the Big Arroyo to the mouth of Rock Creek, the grade steepens gradually to an average of more than 100 feet per mile; and between Rock Creek and Whitney Creek it reaches locally as high as 200 feet per mile. But from the fan of Whitney Creek to Junction Meadow, it again flattens to less than 100 feet per mile.

In many of its geomorphic features, the Kern Canyon, in Sequoia National Park, resembles the Kings Canyon (canyon of the South Fork of Kings River) which adjoins it on the north (Matthes, 1926). Kern Canyon lacks imposing cliffs of massive rock like those above Zumwalt Meadows in the Kings Canyon, but it is a longer and in some respects a more impressive canyon. Its cliffs are composed of sparsely jointed granite, and along many of the vertical or nearly vertical master joints, storm waters have cut clefts, some fully 100 feet deep and with cavelike recesses. Near Junction Meadow, on the west side of the canyon, there are clefts, a hundred yards or more apart, which have been cut along oblique master joints dipping steeply southward.

The floor of the canyon, throughout this section, is so largely covered with surficial deposits that only in a very few places does the river flow over bare rock. Glacial moraines are confined to a small area at the park boundary, but alluvial and talus deposits are extensive throughout this section of the canyon. Undoubtedly some of the material mantling the bedrock floor of the canyon is glacial outwash.

At places where tributary streams join the Kern River, great boulder fans extend out from the walls of the canyon onto its floor. Such a fan, composed of mingled lava and granite boulders, occurs at the mouth of Golden Trout Creek, and across the canyon is the exceptionally large fan built by Coyote Creek at a place where Wisconsin moraines descend to the canyon floor. At the mouth of Rock Creek, the canyon floor is covered with large quantities of bouldery material deposited both by Rock Creek and by the Kern River, but here a distinct fan is lacking. Whitney Creek has a conspicuous fan, and Wallace Creek has an even larger fan which includes much material derived from lateral moraines of the Kern trunk glacier higher on the valley side. Wallace Creek now flows in a steep-walled trench that is cut across the lateral moraines and down through the upper part of the fan.

All the alluvial fans have been truncated by the river at a considerable height above the canyon floor proper. The resultant scarps, though commonly 50 to 60 feet high, vary in height, depending on how steeply the surfaces of the fans slope and on the extent to which these fans have been trimmed back by the river. As a consequence, in some places a scarp on one side of the river may be twice as high as one on the opposite side.

These features are well illustrated by the great fan of Coyote Creek, which is typically truncated by a main scarp 60 to 70 feet above the river. This scarp is old enough to have numerous short gulches worn in it, and the edge of the terrace is therefore distinctly lobate. The lower terrace is nearly 20 feet above the river. A steel suspension bridge is built at this level. Conterno's old suspension bridge, half a mile farther upstream, is built in a less favorable place, where, because the lower terrace is absent on the east side, the trail had to be cut obliquely down the scarp of the main terrace to the bridge.

The partial dismantling of the canyon walls has given rise to long talus slopes which extend along both sides of the canyon. Although these slopes are nearly continuous, there are, nevertheless, many places where rock in its original position crops out near the base of the talus. The talus slopes, which help to complete the U-shaped form of the Kern Canyon (although the canyon would be distinctly U-shaped without them), extend to various heights; near Junction Meadow the slopes apparently reach about halfway up the canyon side, but their exact upper limits are difficult to judge because of the brush cover. A puzzling feature of the talus slopes is the fact that those on the east side of the canyon are for long distances more voluminous than those on the west side. Like the alluvial fans, the talus slopes have been cut back, and scarped, by the river.

In places the canyon floor is encumbered by enormous blocks that have fallen from the bordering cliffs. Many of these blocks, which constitute one of the impressive features of the canyon, can be seen along the trail near Funston Meadows. They measure 10 to at least 50 feet in diameter but, as a result of irregular spalling, most are now much smaller than when they fell.

No true exfoliation was noted in the Kern Canyon, in striking contrast to the many exfoliating granite boulders in the Kings River and upper San Joaquin River basins. The reason for this difference is probably to be found in the occurrence of irregular minor structures in the granite of the Kern Canyon. The rock is full of shear fractures, mostly chloritized, and it tends to spall along these fractures, at least for short distances.

Where tributary streams leave the mouths of hanging valleys on the uplands and descend into the canyon, cascades and waterfalls are found. Several of these are of spectacular height and great beauty, yet are still (1964) unnamed. The most notable waterfalls occur where several streams draining Chagoopa Plateau plunge down the steep west wall of the canyon. Of this group the falls of Red Spur have the greatest drop, about 2,300 feet. Chagoopa Falls (fig. 17) descend by several deep plunges, glissades, and, farther down, broken cascades, a total fall of about 1,400 feet. As a result of stream entrenchment, some of the cascades lie in the bottom of gulches; where stream cutting has been facilitated by fractures in the rock, the gulches may be so narrow and deep that the cascades recessed in them are all but invisible (fig. 18, 51).

FIGURE 17.—Chagoopa Falls, which descends the steep west wall of the Kern Canyon from a small hanging valley on the Chagoopa Plateau. The side valley was left hanging primarily as the result of rapid trenching by the master stream, but its height was increased by glacial deepening of the Kern Canyon. Widening of the canyon by glacial erosion also steepened the descent of the cascades. Photograph by Kenneth Flewelling.

FIGURE 18.—Slotlike gulch incised in the east wall of Kern Canyon by a streamlet descending from the mouth of a hanging valley below Kern Lake. Stream cutting was facilitated here by a fracture in the granite. The cascade is now so deeply recessed as to be almost invisible. This gulch is just outside the south boundary of the park, but similar gulches are found farther north, within the park.

Immediately south of the park, there occur features which have significant bearing on the glacial history of Sequoia National Park (fig. 19). In this area, extending about 7 miles southward from the park boundary, the canyon retains its distinctive broad U-shape but loses some of its regularity and, departing from its nearly straight southward course, swings eastward around Hockett Peak.

FIGURE 19.—View up the Kern Canyon from a point about 2 miles south of the park boundary. Kern Lake, in the foreground, is not a glacial lake; it was formed in 1867-68 when the Kern River became ponded through rapid growth of an alluvial fan. Beyond the lake, in the shadow, appears one of the buttresses (kernbuts) characteristic of this part of the canyon. In the Wisconsin Stage, the Kern glacier reached only to the park boundary, but in the earlier stages it extended several miles farther south and occupied the part of the canyon shown in the foreground of this view. Photograph by W. L. Huber.

Within this part of the canyon are ancient moraines which record the southerly limits of the Kern trunk glacier at one of its early stages. The Kern Lakes, also in this section, are not of glacial origin, however, but came into existence, as Lawson (1904, p. 343-345) correctly recognized, through two special and different causes. Kern Lake is impounded behind the fan of a streamlet coming down from a hanging valley on the east side of the canyon; Little Kern Lake, which is separated from the river by an almost continuous natural levee, is held up behind a dam resulting from a colossal rockslide which fell from the east wall of the canyon.

Of great interest also are the prominent buttresses, in the bottom of this part of the canyon, which Lawson (1904, p. 331-343) regarded as being a type of geomorphic form not previously recognized and for which he proposed the name of "kernbut." Lawson's description of the kernbuts follows, in part:

A remarkable feature of the Upper Kern, below Volcano Creek, is the departure of the stream from the west wall of the cañon and its crowding upon the east wall. This displacement of the stream is due to obstructions in the shape of a series of rocky buttresses, which adhere to the foot of the west wall, and, projecting out beyond the middle line of the cañon, locally, constrict it, causing the stream to occupy narrow gorges between these buttresses and the east wall. In the interval between these buttresses the bottom of the cañon has its normal width of about half a mile from wall to wall. There are several of these buttresses in the vicinity of the Kern Lakes, and the two lakes lie in two of the intervals. In cross profile these buttresses have the character of rather sharp-crested ridges which run parallel to the general trend of Kern Cañnon; and a buttress may be a single ridge or a series of two or three ridges, in which case the latter are successively lower in the east. The buttresses may, therefore, be distinguished as single or multiple according as they present one or more of these ridges in cross profile.

The correlative pass, or col, which intervenes between the kernbut and the main canyon wall or between the parallel ridges of a multiple kernbut, Lawson designated as "kerncol."

The names "kernbut" and "kerncol" were chosen, in part, because they are purely descriptive and carry with them no implication as to the genesis of the forms.