Taming the Colorado

Taming the Colorado A Yellow Flood Becomes a Blue Lake and a Rampageous River Gives Up Its Strength to Live for the Good of Man

By NORMAN G. WALLACE (Photos by the Author) SEVERAL million years ago a sluggish stream started seaward and began to bury itself far beneath the surface of the earth. Until the past year the Colorado River had practically its own way, far beneath the usual haunts of man, tearing at the earth's crust with an irresistable power and defying man entirely. There is no other large river in the world, which starts so far from its mouth and at the same time flows so far beneath the general level of the surrounding country. Far beneath the top of the sandstone mesas of western Colorado and eastern Utah flows this yellow flood and when it arrives in Arizona it has become a bucking broncho of rivers as it tears at the walls of the Grand Canyon for hundreds of miles before it emerges as a raging torrent of mud, water and sand in the lower Colorado River basin. Nearly two thousand miles long is the Colorado River and most of this distance consists of box canyons far below the surrounding terrain. It is only a few miles from the ocean to where the Colorado River becomes of use for irrigation and even here there was the ever-present threat that the river will go on a rampage overnight and flood entire empires of agricultural land. The possibilities of the Colorado River doing stunts quite out of the ordinary is well shown when we look at the results of the 1905 break in the banks below Yuma when the river had

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its own way for nearly two years. It not only made the Southern Pacific Railroad move its tracks and rebuild nearly one hundred miles of new railway, but it started a channel into the below sealevel area of the Imperial Valley which threatened to become a permanent one for many years. It was only after the expenditure of several millions that it was turned back to its original channel.

To harness the Colorado River a dam was absolutely necessary, a dam which would be large enough to withstand the sudden floods as well as to store the entire discharges for use in the lower water periods.

The Boulder Dam is not in Boulder Canyon. The dam is in Black Canyon several miles below the canyon which gave it its name. It was decided by all the experts that the Black Canyon site would be the best place to harness the river, due to cheaper construction costs as well as larger storage capacity.

Black Canyon is well named. Black vertical sides from where the river enters the Black Canyon to a point many miles below where it emerges into the bright sunshine of the Colorado desert, imprison the Colorado River and its yellow muddy current.

To begin to describe the Boulder Dam and the supplementary works in figures would make one forget the small sum of a couple of million. Everything is in millions so there is no use in causing brain fatigue trying to remember the figures. At any rate all records for cubic yards, tons, heights, or any other comparable figures were broken in the construction of the Boulder Dam from the time the "high scalers" began their precarious work in 1931 to September 1, 1935, when President Roosevelt pressed the key at Washington and the first "juice" started vibrating the atoms in the copper cables which stretch out over the Nevada desert toward the vanishing point on the horizon. In such a deep canyon as the Black Canyon with its six hundred foot walls, almost vertical above the river, the first thing to do is to pry down all loose rock from the sides of the canyon where the dam is to be built. This work is turned over to the "high scalers" who dangle at the ends of ropes, and pry off, or dynamite all rock from the size of a peanut to box car size. Perhaps some visitors have noticed the low walls of stone around the dam and the observation points. These walls were put there to catch any rock, small or large that might

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be accidentally knocked off near the top and prevent its taking a six-hundred-foot nose-dive to hit the "hard-boiled hat" of a busy workman far below. A peanut size rock has the speed of a bullet by the time it has fallen from the top of the dam to the river bed where hundreds of men were directly under the cliffs above.

While the high scalers were busy at their jobs, swinging at the ends of their ropes with the blue sky above and noth-ing below but eternity, hundreds of other hard rock men were busy inside the four tunnels which were necessary to bore through both sides of the river in the solid rock. These tunnels were to carry the entire flow of the Colorado River around the dam while it was un-der construction. They were fifty-six feet in diameter-large enough to put a good-sized house within, and were each over four thousand feet long.

The biggest job in this tunnel work was to dispose of the broken rock and debris as it was blasted out. Dozens of trucks roared day and night for months, hurrying the muck out of the tunnels up the sides of Black Canyon and to gulches where it could be dumped without cluttering up the river channel. They even had to make more tunnels to reach spots where the trucks could be dumped and turned around. All this work was done down in the depths of the Black Canyon along almost vertical cliffs.

Many other activities went on at the same time, such as railroads to the gravel deposits up the river on the Ari-zona side, crushing plants to break the gravel and make it of uniform size for the concrete, roads to many points at the dam site. Thousands of men were busy for months before the first wrestling with the Colorado River was at-tempted. All this time the Colorado River flowed undisturbed and seemingly unafraid of the puny efforts of the human ants swarming along its black canyon walls.

On November 13, 1932, the Colorado River was rudely awakened from its sleep of the ages, and its dream of irresistable power. Some one touched a switch and a dull roar of exploding dynamite echoed in the Black Canyon. The Colorado River awoke with the sudden anger of a disturbed grizzly bear, tore at the man-made barricade the ants had constructed while it was asleep, swished and tore its way along the ob-

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