Lake Mead

One of the greatest thrills to be experienced on Lake Mead is a boat ride over its shimmering blue waters to one of the many delightful spots where fishing, swimming and photographing spectacular scenery makes the outing a happy one. Photo above, by J. Benedick, left, Wm. Belknap.

The world's largest artificial body of water, backed by the highest barrier on earth and controlling the once tortuous Colorado River, makes of the Boulder Dam National Re-creational Area one of the most popular playgrounds in the United States. It is described by seasoned travelers as one of the most exciting adventures in any travel itinerary. Lake Mead, formed by the construction of Boulder Dam, extends 115 miles up the Colorado, through Boulder Canyon, Virgin end of the Grand Canyon. With the creation of this lake, water backs into remote box canyons never before accessible to man. Miles of cliffs, buttes and sandstone temples, flaming with color, are reflected in the placid waters, creating a scene of unmatched beauty.

Lake Mead has a shore line of 550 miles and holds more than 30 million acre-feet of water. The reservoir's depth at the dam is more than 550 feet. From the crest of the dam can be seen great schools of big-mouth black bass, many of exceptional size. Fishing is good on Lake Mead, either from boats or along the banks of the lake and its many coves.

Superstition mountain on pages 22 and 23 is from a Kodochrome by Don Keller.

This mighty lake is one of the finest for motor boating, sailing and canoeing. It is under the supervision of the Na-tional Park Service. Fortunately for the people of America, this spectacular area is administered as a public enterprise for the pleasure and the enjoyment of all.

On a boat trip many awe-inspiring sights come into view. The sheer white cliffs of Temple Bar and the stately form of Napoleon's Tomb rise in bold relief from the vari-colored cliffs and reflect in detail in the mirrored waters far below them. The mile-high walls of Grand Wash Cliffs give way to a peninsula overlooking Pierce Ferry, a recreational center which undoubtedly will include hotels and other resort facilities as the area is further developed. Nearby, is the magnificent Joshua Tree Forest, through which a forty-five mile stretch of road wends its way from Pierce Ferry to the King-man-Boulder Dam paved highway.Back in the Grand Canyon country gleams Emory Falls. a 150-foot ribbon of water that drops gracefully from the red cliffs into a veritable garden of mosses, ferns and wild grape vines.

Bathing facilities are available at Memenway Beach, a short distance above Boulder City. Here also is a boat landing where many types of water craft are anchored.

More massive than the Pyramid of Cheops, Boulder Dam was built by 4,000 men in four years, whereas the Pyramid consumed in its construction the labors of 100,000 men for a generation. The magnificence of Boulder Dam is not dependent upon its tremendous size. Its accomplishments are even more impressive, despite the perfection of its design and its simple beauty. They are not so readily seen and understood, however. While it has set a new high in engineering achievement, Boulder Dam will be noted in the future for the good it does, rather than for its magnitude or appearance.This great barrier in Black Canyon, braced as it is against the cliffs of Arizona on one side and the precipitous wall of Nevada on the other, brings under control America's most turbulent river. It provides an unfailing water supply for hundreds of irrigated farms in the deserts and supplements the domestic supply of thousands of city homes in the Southwest, By storing the torrential flow of the Colorado for release steadily throughout the year. It has created mighty Lake Mead, thus making a new national playground. It controls the silt of the river, and it makes possible the generation of hydro-electric power sufficient to repay the entire cost of the project, 108 million dollars, in 50 years, with interest at 4 per cent.

The character of the Colorado River has been changed entirely. A menace has been transformed into a new source of wealth. The dam, through its benefits, will add thousands to the population of its environs, even as other great dams in Arizona, already constructed, and still others now being planned.

Some of the figures in connection with the construction of Boulder Dam stagger the imagination. Five million barrels of cement were used, mixed with sand and gravel to make four and one half million cubic yards of concrete. Almost 600 miles of pipe are imbedded in the concrete, through whichice water was circulated, to cool the mass as it was poured. An ice plant capable of producing two million pounds of ice a day was placed in operation. Eighty-eight million pounds of plate steel was used to make pipe, some of which measured 30 feet in diameter. Twenty-two million pounds of assorted gates and valves went into the construction of the dam proper, as well as nearly 20 million pounds of structural steel, nuts and bolts. These items make up but a small portion of the supplies which were required.

Boulder Dam's great height of 727 feet, with a base 660 feet thick and tapering to 45 feet at its crest, which is 1,282 feet long, is actually dwarfed in its majestic setting of rugged and colorful mountains. The dam is of arch gravity type-a construction in which water load is carried by both gravity and arch action. The technical design of the dam was based on three fundamental requirements; first, that the dam should be of the massive arch-gravity type; second, that the base of the dam should be located wholly within the area bounded by the two adjacent fault lines in the canyon rock; and third,that the maximum compressive stress in the dam should not exceed 30 tons per square foot. Two of the most important and difficult problems in the design and construction of the dam were the generation of heat in a large mass of concrete due to hydration of cement, and the volumetric changes occurring in mass concrete due to temperature changes and other causes. That is why provisions were made to include circulferential contraction joints in the dam and to lower the temperature of the concrete to normal, or subnormal values, by means of an artificial cooling system. Aside from the great concrete wedge, the giant spillways and intake towers, and the intricate network of power facilities, the dam houses batteries of the world's largest generating units, with an ultimate installation of 15 main generating units of 115,000-horsepower capacity each, making a total generating capacity of nearly two million horsepower.

Boulder Dam and Lake Mead are overpowering in their immensity and many-fold purposes truly one of the greatest engineering achievements in the history of man.