The dam that remade the American West celebrates its 75th anniversary
For 12 million years it trickled, meandered, and snaked, before bursting violently loose to slash to its final destination. Then, one winter day in 1935, this ancient, tempestuous journey abruptly ended in a remote canyon as the last of more than 5 million buckets of concrete was poured onto the crest of a 726-foot wall that blocked its path. Observers watched in awe as the nation’s wildest river puddled up behind the massive structure. Soon the benign-looking pond would reach back for 115 miles to a depth of 500 feet, the largest human-made lake in the world.
On September 30, 1935, the usually eloquent 32nd president of the United States was rendered “speechless” at the sight. Franklin Delano Roosevelt had made the arduous journey from Washington, D.C., to this southern Nevada wilderness to dedicate the “Eighth Wonder of the World.” “This morning I came, I saw, and I was conquered, as everyone will be who sees for the first time this great feat of mankind,” declared Roosevelt, as if sharing the subjugation of the Colorado River.
A symbol for all that was right and wrong with America, Boulder Dam (renamed Hoover Dam in 1947) was an incomparable triumph. Raised in the depths of the Great Depression, under the most harrowing and brutal circumstances, by some of the nation’s poorest, most desperate men, its raw power made it a towering metaphor for the nation’s ability to overcome disaster. Conceived by a river runner turned civil engineer, facilitated by an ambivalent president, micromanaged by an egomaniacally ambitious contractor, overseen by a mild-mannered bureaucrat, and built by circus acrobats, Indian skywalkers, and hordes of the unemployed, the greatest engineering achievement in American history to that date was a perfect confluence of unlikely characters and events.
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By the early 1920s southern California was growing by leaps and bounds and had set its sights on the Colorado River as its source of both water and electricity. Fewer than 10 million people lived in the American West, with more than half in California. Even though the Golden State contributed little to the Colorado River, the headlong eager developers of Los Angeles and San Diego began pushing Congress to authorize a dam that would primarily benefit California, with nearly two-thirds of the hydroelectricity it generated going to light up Los Angeles. The other six riparian states naturally bristled at the notion—especially Colorado, Wyoming, and Utah, which contributed more than 83 percent of the runoff between them.
On November 24, 1922, representatives of the seven states gathered in Santa Fe to divide up the river’s annual estimated flow of 17.5 million acre-feet of water. Guided by Commerce Secretary Herbert Hoover, they negotiated the Colorado River Compact, which separated the river basin into “upper” and “lower” divisions, arbitrarily partitioned at Lee’s Ferry, Arizona, and allotted 7.5 million acre-feet to each segment. Whatever was left would go to Mexico. But despite the agreement among the gathered experts, the legislatures back home would not ratify the compact.
Meanwhile, hydrologists and geologists for the U.S. Reclamation Service—the branch of the Interior Department that would later become the Bureau of Reclamation—were exploring the lower Colorado for the best spot to build a dam. For six more years the states bickered, while Eastern politicians balked at spending millions on an involved project in the sparsely populated hinterland. Finally Congress took control and authorized construction of a dam near the Nevada-Arizona border.
For a quarter century Arthur Powell Davis had envisioned backing up the Colorado River near the walls of Black Canyon. A civil engineer, hydrographer, and nephew of explorer/geologist John Wesley Powell, he had mapped every inch of the river and many of its canyons and deserts. Davis conceived of a dam built in the hottest, most desolate stretch of the Colorado, and for decades had fought strenuously to see it built. As director and chief engineer of the Reclamation Service, he crafted a scientific study of the river and its canyons, a document notable for its exhaustiveness and precision. But the significance of its graphs, maps, and scientific data was lost on the small-minded bureaucrats, developers, and politicians who were its audience.
Genteel and dignified, Davis lacked the disposition to endure the vicious internal and external strife surrounding such a massive project; like his uncle, he ultimately became disenchanted, if not disgusted, by the political process. He resigned the position where he had spent the past four decades and retreated to California, relegated to the sidelines as his brainchild rose from the rugged canyon floor.
Equally obsessed with the vision of a dam on the Colorado was Frank T. Crowe, a legendary engineer who was often compared to George Washington Goethals, the hard-driving Army officer who oversaw the building of the Panama Canal. Born in Quebec in 1882, Crowe had studied civil engineering at the University of Maine. So eager was he to begin his dam-building career that he skipped his 1904 commencement to work in the field for the U.S. Reclamation Service. Crowe spent the next 20 years in river bottoms, building dams in Idaho, Wyoming, and Montana, all the while angling to become the contractor for the nation’s most ambitious dam.
The six-foot-three Crowe combined an imposing physical presence with an engineering and managerial proficiency that impressed both peers and subordinates. Cultivating contacts within both the public and private sectors, he took an energetic part in the early design work. “He was wild to build that dam,” according to his biographer, Al M. Rocca. “This was his dream. And he wanted to be known as the greatest dam builder who ever lived in America.” By 1924 Crowe had become the general superintendent of construction for the Bureau of Reclamation; a year later the government thwarted his ambitions with a decision to hire private contractors for massive public projects.
The man whose motto was “Never My Belly to a Desk” left the government and joined Six Companies, a consortium of independent Western contractors who had partnered to bid on the dam, a job too big for any one of them individually. As the inventor of many of the techniques to be used, Crowe would become the consortium’s secret weapon. He soon became its chief executive and superintendent of construction. Composed of rival firms from Idaho, California, Utah, and Oregon, Six Companies and its most famous partner, W. A. Bechtel of Oakland, constituted the first megacompany in the American West.
As a former government insider who was intimately acquainted with all 119 of the bureau’s complicated specifications, Crowe crafted the consortium’s bid to total just $48,890,955—only $24,000 more than government engineers had calculated. Not surprisingly, on March 4, 1931, the bureau awarded the contract to Six Companies, whose offer—as Crowe well knew—was the lowest among the competition. For that amount, Six Companies was responsible for all construction costs, including dynamite, vehicles, salaries, and wages, while the government absorbed the cost of cement, steel plates and castings, and any machinery required for permanent operation of the dam. “When the last bills are paid and the turbines begin to turn,” reported Fortune magazine in 1933, “the Six Companies will have turned a profit estimated at $7 million and upward for all their work.” Despite congressional grumbling, the government did not begrudge the company’s seemingly astronomical profits. “The U.S. is willing to pay a good profit for a good dam built rapidly,” as Fortune put it. At $165 million, the Boulder Canyon Project Act would be the largest congressional appropriation in American history until that time. It was signed into law by President Hoover, long the dam’s champion and in due course its namesake.
The government’s plan called for a 6-million-ton curved concrete arch, tall as a 60-story skyscraper, wide as two football fields at its bedrock base, and embodying enough concrete for a 16-foot-wide highway from San Francisco to New York City. Six Companies would have to move 10 million cubic yards of rock, build the era’s largest hydroelectric power plant, create a massive reservoir, and immediately erect the town of Boulder City to house more than 5,000 workers. All this was to be accomplished under a series of daunting deadlines and heavy fines for missing them.
Naysayers doubted that such a large structure, placed as it was between two fault lines in the canyon floor, could maintain its stability. Many informed scientists predicted that the weight of the lake created by the dam would provoke a ruinous earthquake and “unleash a flood of biblical proportions.” One engineer recalled that “we were all scared stiff.” Though Crowe had overseen the construction of six dams, none had presented such tremendous obstacles—and in such rugged, inaccessible terrain—as the rock cliffs of Black Canyon.
A week after winning the bid, Crowe took the Union Pacific Railroad from Denver to dusty Las Vegas and made his way to the isolated dam site 30 miles to the southeast. Joining him was the refined, bridge-playing Walker Young, the bureau’s construction engineer. The highest-ranking official on the project, Young served as the chief liaison between Six Companies and the bureau. Where Crowe was impetuous and demanding, Young was thoughtful and tolerant. Though they could not have been more different in temperament, they were joined in a passion for the project that would prove the capstone of their careers.
“This will be a job for machines,” Crowe told the New York Times. Indeed, the scale and development of modern machinery immediately set this project apart. Mack engineers built the largest truck ever—a massive 250-horsepower vehicle capable of moving 16 cubic yards of earth. General Electric constructed the most sophisticated X-ray unit of its time in order to take 24 million square inches of photographs of pipe welding. Ledgerwood Manufacturing produced steel ropes 3½ inches in diameter that could lower 150 tons of concrete or steel into the construction pit. A 29-year-old assistant superintendent designed and built a motor-driven rig set on a 10-ton chassis that supported four massive platforms mounting 30 144-pound rock drills. This ingenious invention would become the project’s historic signature device, enabling the vehicle to be positioned to drill and then be driven away before dynamite exploded.
The first task at hand was the most complicated and treacherous: diverting the Colorado through four 56-foot-wide tunnels, two on each bank, which would draw the river out of its course and leave the original riverbed dry for construction to begin. Workers drilled and dynamited through 3.5 million tons of volcanic rock to build these three-quarter-mile-long tunnels, each as wide as a four-lane highway. Three feet of concrete, manufactured a mile upstream at a plant erected by Six Companies, would line each tunnel. Sand and gravel were combined into aggregate, then blended with cement and water. Workers poured the base from cranes that rode on rails through the length of the tunnels. Next the side walls were poured in steel forms. Finally, the overhead was filled in with pneumatic guns. Each tunnel could carry 200,000 cubic feet of water per second.
Barges carried gas and diesel generators, jackhammers, air compressors, and an entire blacksmith shop to the site. Meanwhile, access roads and a 30-mile railroad system linked the site with gravel pits, and power lines were strung. At the height of the first phase of construction, more than 1,200 men worked as miners, nippers, chucktenders, muckers, shovel operators, drivers, cat skinners, electricians, and powder men.
“High scalers” performed the most daring jobs, rappelling along the sheer cliffs, stripping them clean of any loose rocks and scree fields that could break loose and hurtle down upon the workers below. (The smallest rock kill a man outright.) The walls also needed to be completely free of debris where the concrete dam and the canyon would meet. No cranes could do the job, so it was left to the 400 high scalers. Known for their agility, guts, and good-natured showmanship, the acrobatic workmen carried their tools and water bags up the towering walls like performing monkeys, held only by slender ropes. Once situated at their workstations, suspended in swinglike seats bolted to the rock, they pulled out their 44-pound jackhammers, drilled holes, and inserted dynamite. Few of the other laborers begrudged them their 40 percent bonuses. Former sailors, ironworkers, and circus performers, they were innate thrill seekers, regularly performing stunts and competing athletically to catch the eyes of their colleagues—daredevil antics that irked Frank Crowe.
Called “Hurry-up Crowe” for the breakneck speeds he demanded—which led to even greater profits—he worked his laborers hard in summer temperatures that averaged 119°F. With no shade and little fresh drinking water, the casualty list was alarming. In one five-day period alone, 14 workers died from heat prostration. It took a visiting team of Harvard University physiologists in the summer of 1932 to determine that dehydration was a leading cause of death. The diversion tunnels often reached a smothering 140°F and were thick with carbon monoxide, which killed many. Six Companies deliberately misdiagnosed these deaths as pneumonia to skirt legal culpability.
Even with Crowe pushing hard, cutting this new channel took 18 months. Before the Colorado was finally diverted, workers raised a 98-foot-high cofferdam on the Nevada side, 600 feet downriver from the inlet portals of the diversion tunnels. On November 12, 1932, a week after being voted out of office in a landslide, Hoover made his final visit to the already massive project. Crowe guided the lame-duck president through a tour of the dam site that would face its first critical trial the following morning. As a disheartened Hoover left Boulder City on November 13 for his home in Palo Alto, California, at 11:30 the entrances and exits of the two Arizona tunnels were blasted open. Within seconds the first of more than a hundred trucks, loaded with rock and muck, lined up in a convoy from a downstream trestle bridge and dumped its load into the river’s path. Every 15 seconds thereafter into the evening, another vehicle in the conveyor belt dumped debris into the river’s path. The next morning the river was visibly struggling to keep to its ancestral course. At 7:30 a.m. it churned in frustration against the crest of the cofferdam and suddenly shifted along the path of least resistance into the shiny new tunnels. At first the dozens of onlookers, drawn from the national media, workers, and their families, stood in silence. Then, as the impact of what had been wrought sank in, whoops and hollers resounded between the canyon walls.
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Work continued apace for another year. First the upriver cofferdam was strengthened and a second 66-foot cofferdam built downstream; then the engineers turned their attention in earnest to the 700-foot concrete dam and began digging down to bedrock to lay the foundation. One and a half million cubic yards of silt and gravel were dredged and hauled away. On May 31, 1933, workers fired the last 6,000 sticks of dynamite after striking bedrock 139 feet below the surface of the river. The river bottom was pumped dry through a network of pipes, its solid-rock floor cleaned and prepared finally to make possible the concrete-pouring phase of the famous convex arch.
A week later, on the morning of June 6, an eight-cubic-yard bucket, suspended from a giant cable spanning the gorge, teetered for a few seconds before plunging 800 feet to dump its load—the first of the 60 million tons of concrete that would form Hoover Dam’s pristine, futuristic face. Presenting engineers with the most challenging aspect of the entire project, the dam’s size and weight would generate and retain so much heat from the continuous pour that it would haven taken more than a century for the concrete to cool under normal circumstances. To resolve that difficulty, a series of vertical columns, each containing an estimated 215 concrete boxes, were built up from the depths of Black Canyon. The blocks varied in size from 25 square feet on the dam’s downstream face to 60 square feet at the top; the columns were interlocked Lego-like, through a system of vertical keys on the radial joints and horizontal keys on the circumferential joints. Through the concrete threaded 582 miles of one-inch steel pipe laid at five-foot intervals, circulating chilled water from a nearby refrigeration plant that produced a thousand tons of ice per day. The reputations of Crowe and Six Companies—not to mention the stability of the dam itself—depended upon the viability of this block-by-block strategy. Brilliantly conceived, the plan proved successful, as the cooling rate could be accelerated and then monitored by electrical thermometers. Once the blocks had cooled, a pasty grout of cement and water was pumped into the pipes to form a solid structure invulnerable to hairline fissures.
The “pour” went on 24 hours a day, seven days a week, for nine months, with a bucketful of concrete dropping every 78 seconds. Simultaneously, workers began building two giant spillways, four 395-foot-high intake towers, and several 30-foot wide, 170-ton penstocks to carry water from the intakes to the turbines, as well as a 222-mile-long power transmission line from the dam to southern California. Meanwhile, two of the four diversion tunnels were permanently sealed, and a third was plugged with a perforated gate fitted with four valves that could be opened or closed as needed to irrigate California’s Imperial Valley farms. On January 31, 1935, a steel bulkhead gate weighing more than a thousand tons was lowered onto the canyon floor, closing off the fourth and final tunnel. The Colorado River, now barricaded from its long-worn course, began pooling behind the streamlined monolith to create Lake Mead. The next week, on February 6, the last bucket of concrete was poured on top of the 726.4-foot dam.
Completed two and a half years ahead of schedule, using three and a quarter million cubic yards of concrete, employing 21,000 famously taut and muscled men, and claiming the lives of at least 112 workers, Boulder Dam glared white against the desert canyons. Some saw it as a tribute to technical ingenuity, a symbol of humanity’s conquest over nature, of hope over despair. “For a nation deeply wounded by the Great Depression . . . ,” wrote historian Joseph E. Stevens, “Hoover Dam was not only a triumph of individual[s] . . . [but it] was also a collective national triumph, a stunning example of what private industry, government, and labor, working together, could accomplish for the betterment of all.” Others saw it as the beginning of the end of the natural West, a devastating ecological insult—what environmental historian Marc Reisner called “the most fateful transformation that has ever been visited on any landscape, anywhere.”
However history ultimately judges it, this marvel of design, engineering, architecture, and construction stands as an emblem both of the subjugation of the American frontier and of the New Deal’s boldly experimental marriage of public welfare and private enterprise.