WATERFALLS

By Dr. Harold C. Bryant,
Public Works Consultant.
(Formerly Supervisor of Research and Information).

Even if you haven't visited Niagara Falls on your honeymoon, somewhere you have seen water dropping over a precipice small or large, felt the spray on your face, and heard the endless roar. A boyhood memory of mine is of a trip to Eaton's Canyon, above Pasadena, California, to the Fall, perhaps fifty feet high. Even with later views of the great among waterfalls, memory of this lesser one holds a vivid place in my mind, for my childish question was why the water did not stop falling instead of furnishing a continuous roar.

The older the stream of water, the less spectacular are its waterfalls, for waterfalls and rapids belong to youthful streams. Most often a waterfall develops in streams that have net yet acquired a graded slope, but some appear as a result of some outside force causing an interruption. A lava flow or a landslide, a glacial moraine, an uplift or a fault line may produce proper topography for a waterfall. The first, or normal type, is formed by variation in the hardness of rocks into which the stream is cutting; in other words, unequal erosion. And of course a waterfall accentuates inequality by successfully increasing the rate of erosion below the fall. Falls due to vertical beds of hard rock seldom change their position, but those having horizontal beds, or beds dipping slightly upstream, slowly retreat upstream and become lower. The Niagara River flows over horizontal beds of hard limestone, superimposed on weak beds of shale. At the base of the falls the soft beds are cut away, allowing great blocks of hard limestone to break off. The fall has continuously moved upstream seven miles in about 20,900 years.

Shattered rock, between masses of resistant lava, helped the Zambesi River in Africa dig out a 400-foot canyon at right angles to the river valley, and produce the famous Victoria Falls. Sometimes the sapping process of a great glacier makes canyon walls perpendicular, and side streams may drop over great cliffs to a glacial-cut canyon below. Such is the explanation of Yosemite Falls, in Yosemite National Park, California. The Takakaw Falls, in the Yoho Valley of British Columbia, carry a glacial stream into an ice-carved canyon. Nor must we forget the series of waterfalls to which the name of cascade is given. Water flowing over an inclined bed is known as a rapid. Sound and speed begin with a rapid increase in the cascade, and meet the maximum in a clean fall from an overhang.

There is great inspiration appeal to the person viewing a waterfall. The whiteness of the water, the rockets, the contour of the lip, stir the senses of sight; the movement of cooled air, the spray on the face, bring tactual sensations; the damp odor of running water pleases the nostrils, and the ear may catch the whole gamut of water music from the soprano of the tiny fall to the basso profundo of a great cataract.

YOSEMITE, WORLD'S HIGHEST FREE LEAPING FALLS.

The National Park System is blessed with a fair share of the continent's greatest waterfalls, in addition to the innumerable beautiful falls that are found wherever mountainous regions abound in running water. There is Mount Rainier, in Washington, with its array of beautifully named falls: Narada, Christina, Spray, Comet, Ethania and Fairy Falls to the south and west; and its Stafford, Sydney, and Silver Falls, in the Ohanapecosh section. Visible to every main entrance visitor is Shuskin Falls, near Paradise Valley. In practically all these, water is supplied from melting glaciers, and glaciated canyons form the setting.

Glacier National Park, Montana, is a land of falling water. Any trail to the high country leads along glacial streams which fall in steps from the melting face of some glacier. Numerous white cascading streams drop over precipitous heights to glacial valleys below. The head of Avalanche Creek, above Avalanche Lake, furnishes a spectacular array of such streams. One trail is termed Many Falls Trail because it leads by so many waterfalls. A noted fall in the Bowman Lake country bears the name of Hole-in-the-Wall Fall. Another freak fall below Two Medicine Lake is properly termed Trick Falls, for when the stream carries plenty of water it forms a normal waterfall, but when the stream is low, water rushes out of a hole in the rock wall below the lip of the falls.

A trip to Chasm Fall in Rocky Mountain National Park, Colorado, is rewarding of effort. The Great Smoky Mountain National Park, in Tennessee and North Carolina, comprising the most massive mountain uplift in the East, and with heavy rainfall, naturally has plenty of running water with accompanying waterfalls. The most noted is Rainbow Fall. Shenandoah National Park, Virginia, has less spectacular streams and waterfalls but they are of sufficient beauty to stimulate visitors to take the trails. Devil's Postpile National Monument, California, possesses a fall of note. The whole northfork of the San Joaquin River plunges over a natural lava dam to form Rainbow Fall, spectacular because of the large volume of water. Glacier Bay National Monument, in Alaska, contains plenty of yet unnamed falls, such as accompany glacial conditions.

Yellowstone National Park, Wyoming, possesses two falls on the Yellowstone River that are spectacular because of size and location at the head of the colorful Grand Canyon of the Yellowstone. The artist and photographer have marked these falls, twice the height of Niagara, as furnishing a scene of superlative beauty. A trail leads to the foot of the Lower Falls so that the visitor may see the spectacle from observation points along the rim of the canyon, or more intimately from the winding trail to the bottom. Nor must the Bechler Basin country be forgotten with its Cave Falls and other smaller ones.

The park with just the proper topography to present waterfalls is Yosemite. Here we find several superlatives. On the way in we pass Cascade Fall, and at the gateway to the valley, we see Bridalveil Fall, 620 feet in height, a perfect type falling over a vertical precipice. Because the water and the spray of the latter are wafted back and forth by a breeze, the Indians called it Pohono, the "Fall of the puffing winds." Late in summer this fall often turns to spray entirely and is wafted up as well as sideways. Early in spring we may catch glimpses of Ribbon Fall, to the left of great El Capitan, which is highest of all if we do not demand a clear drop, 1,612 feet. To the right, up the valley, is Silver Strand, more familiarly known as Widow's Tears, which has a drop of 1,170 feet. Then from a notch on the north, Yosemite Falls, highest of its kind in the world, looms into view.

Mr. Francois Matthes of the U. S. Geological Survey, has gathered statistics of all the great waterfalls of the world and has concluded that Yosemite Falls surpasses all others in height and splendor. Even though formed by only a tributary of the Merced River, they constitute the most spectacular feature of the valley proper. Composed of a great upper fall, an intermediate chain of cascades, and a smaller lower fall, the combined height is 2,565 foot. The Upper Fall, with its drop of 1,430 feet, 1,360 of which is a clear leap, constitutes what is believed to be the highest free leaping waterfall in existence. Most waterfalls of great height in other countries for which superlative claims have been made, either prove to contain cascades, or the measurements have been exaggerated.

Mr. Matthes, in his "Geologic History of the Yosemite Valley", (U.S. Prof. Paper 160, P. 20-21) lists numerous great waterfalls of the world, including Takakaw in the Yoho Valley of British Columbia (1,346 feet with partly free leap of 900 foot); Akaka of Hawaii; Basaseachic of Mexico; Tequendamas on the Bogota River, Columbia; Kaietur of British Guiana (822 feet of the 400-foot-wide Potaro River); Staubbach of Switzerland, the Voring Fos (1,150 feet), and Vettis Fos (853 feet), of Norway; Gavarnie of the French Pyrenees (two leaps of 958 and 427 feet); Kalambo of Southern Africa (1,200 feet); the Gersoppa (830 feet) on the Sharavati River of South India; Wooloomumbi of New South Wales; and the Stirling, Bowen and Sutherland (1,904 feet divided into sections of 815, 751, and 338 feet) of New Zealand; but gives Yosemite Falls the lead as a leaping fall, and also as a chain of falls 2,565 feet in height. Mr. Reynold Carlson in "Which is the World's Highest Waterfall?" (Yosemite Nature Notes, 14, pp. 1-8) also confirms this view. Because Yosemite Falls often disappears entirely in late summer, many have advocated a storage reservoir to keep it running. The California State Legislature once passed a resolution urging this artificiality which, of course, the National Park Service opposes.

As second in height in the United States, Tueeulala Fall in the Hetch Hetchy Valley of Yosemite National Park, is cited with its total estmated height of 1,000 feet and its clear fall of 600 feet. Multnomah Fall, in the gorge of the Columbia, in Oregon, makes an essentially unbroken descent of 700 feet.

NAVAJO FALLS, GRAND CANYON.

An enormous ice cone forms at the foot of Upper Yosemite Fall each winter. Measurements showed this ice cone to be 173 feet high onFeb ruary 7, 1936, and 247 feet high on February 28 of the same year. Maximum calculation from a photograph showed a cone 322 feet high with a base comprising 160,000 square feet, or 3.7 acres, with a total of 25,000,000 cubic feet of ice and snow.

The whole Merced River plunges over two great falls in Yosemite, best viewed from Glacier Point. The great Nevada Fall measures 594 feet, the water issuing from a narrow rocky gorge; and Vernal Fall, in the form of a broad green curtain, drops over a vertical cliff 317 feet in height. The Indian name Yanopah, meaning "cloud of water", has reference to the dense spray which rises from its foot. Adding to the beauty of those major falls are the series of cascades between them. Of particular note is a broad white one entering Emerald Pool, and very properly named the Silver Apron, because of the thin sheet of water rushing over the smooth granite.

Another stream, the Tuolumne River, within Yosemite National Park, descends by a great series of waterfalls and cascades from Tuolumne Meadows to Pate Valley and forms, as John Muir said, the "crowning glory of the canyon". It surpasses in volume, extent and variety "any other canyon in the Sierra." For miles the stream is white with foam and spray, with only occasional green pools. Below White Cascades, California, and Le Conte Falls, we find the unequaled spectacle of Water-wheel Falls, a series of great fountain-like jets of white foaming water, thrown fifteen to thirty feet in the air by holes in the steep granite bed of the stream, which give the appearance of turning round and round like a wheel. Now reached by trail from Tuolumne Meadows, this astounding piece of water magic is the mecca of thousands each year.

Even Grand Canyon National Park, Arizona, is blessed with cascade-like falls at Roaring Springs and at Thunder River, now reached by trail, where great streams of water gush out of nearly perpendicular cliffs and rush hundreds of feet down to canyons below. At the head of Clear Creek is found Cheyava Fall, which issues from a large cave, and like the others, cascades steeply down to a canyon.

Because of the esthetic appeal of a waterfall, thousands of park visitors make trail-trips to out-of-the-way places to enjoy what the parks offer in falling water. Fortunately the earlier threats that some would be used as power sites have faded, and we can look forward to an unmarred Vernal in Yosemite, and an unharnessed Yellowstone Fall in its colorful setting. This is because the government has appreciated scenic values above economic use, and has protected many superlative ones in the national parks for the benefit and enjoyment of the people for all time.