50 Fun Facts About Hoover Dam

Hoover Dam was built in which gorge of the Colorado River?

Black Canyon is where the dam rose; a study had first recommended another canyon upstream, and the whole project kept that earlier canyon's name even after engineers moved the site.

Hoover Dam straddles the border between Nevada and which other state?

Arizona is on the dam's eastern side; because the two states keep different time zones, a walk across the 45-foot-wide crest can move a visitor's watch by an hour.

Hoover Dam is roughly 30 miles southeast of which major city?

Las Vegas, about 30 miles northwest, was a town of roughly 5,000 when the dam was approved; thousands of jobless men poured in and camped nearby, hoping to be hired.

Which president dedicated Hoover Dam without once mentioning Herbert Hoover's name?

Franklin D. Roosevelt opened his dedication speech on September 30, 1935, with 'This morning I came, I saw and I was conquered' and never once spoke his predecessor's name.

Lake Mead and its shores became the first of which kind of U.S. park unit?

National recreation area was a new label when the Park Service took charge of the reservoir's shores; the country's first, it now draws millions of boaters and swimmers a year to a lake that didn't exist before the dam.

Hoover Dam rises about as high as a building of how many stories?

60 stories is the usual comparison for its 726 feet; the world's tallest dam when it was finished, it is no longer even America's tallest, overtaken in 1968 by an earthfill dam in California.

What structural type of dam is Hoover Dam?

Concrete arch-gravity describes Hoover: 660 feet thick at the base, its curved upstream face carries the water's thrust into the canyon walls while its sheer weight resists overturning.

Which state that Hoover Dam doesn't touch receives the largest share of its electricity?

California takes more than half of the dam's electricity; the project was meant to be self-supporting, with sales of its power paying back the cost of construction.

In the 2007 film Transformers, what does Hoover Dam secretly house?

Megatron's frozen body is kept inside the dam by the secret agency Sector Seven; in the film's backstory the dam was built around the AllSpark so its concrete would hide the cube's energy.

In which 2015 disaster film does a massive earthquake collapse the dam?

San Andreas (2015) stages its first big set piece at the dam, where Paul Giamatti's seismologist watches a quake tear it apart; the 1978 Superman had already burst it on screen.

Which California lake formed when the Colorado River burst through a canal in 1905, spurring calls for a dam?

Salton Sea filled a dry basin when the river poured through a failed irrigation cut; the breach took about two years and $3 million to close, and became the standing argument for a big dam upstream.

Which town was built specifically to house Hoover Dam's construction workers?

Boulder City was run as a federal reservation: a government-appointed manager could evict anyone he chose, and alcohol and gambling were banned outright.

Lake Mead holds which US record?

Largest reservoir by volume in the United States when full, Lake Mead last topped its spillway gates in 1983; long drought has since pulled it to its lowest levels since it first filled.

Which firm won the contract to build Hoover Dam in 1931?

Six Companies, Inc. pooled builders such as Bechtel, Kaiser and Morrison-Knudsen because none could post the bond alone; its bid of about $48.9 million landed within $24,000 of the government's own estimate.

Which superintendent drove Hoover Dam's construction to finish two years ahead of schedule?

Frank Crowe got into dam building as a Maine engineering student, signing up for a summer job with the Reclamation Service before a guest lecture had ended; he stayed for 20 years.

What were the Hoover Dam workers called who dangled from ropes to blast loose rock off the canyon walls?

High scalers hung from ropes to drill and blast loose rock from the canyon walls; they swung out to perform stunts when foremen weren't looking, and one once caught a falling engineer in midair.

Which safety gear did Hoover Dam workers improvise from cloth and coal tar?

Hard hats at the dam began as cloth hats that workers coated in coal tar; after men struck by falling rock broke their jaws but not their skulls, the contractor ordered factory-made ones by the thousands.

Had Hoover Dam been poured as one continuous mass, how long did engineers calculate the concrete would take to cool?

125 years was the estimate for a single pour, and the stresses would have cracked the dam; so it rose as interlocking blocks laced with pipes that carried river water, then refrigerated water, through each one.

During World War II, how did civilian traffic cross Hoover Dam?

In escorted convoys: the dam shut to visitors on the day of Pearl Harbor and stayed closed until 1945, because its power fed wartime aircraft factories and soldiers guarded every crossing.

Each pour raised a Hoover Dam block by mere inches, a fact that debunks which legend?

Entombed workers are a legend the dam's operators flatly deny: a crew of men stamped down every fresh layer of concrete, so a body could not have gone unnoticed.

Hoover Dam's official death toll of 96 leaves out 42 workers whose deaths were recorded as which illness?

Pneumonia was the recorded cause for 42 workers left off the official list, which counts only accidents at the site such as falls, blasts and rockslides; deaths from heat or illness were never included.

Which Interior Secretary ordered in 1933 that the Hoover name be dropped from the dam?

Harold L. Ickes, widely thought to dislike Hoover, said the dam's pioneers had known it by its old project name; in fact Congress had already written Hoover's name into five spending bills.

Which president signed the resolution that restored Herbert Hoover's name to the dam?

Harry S. Truman signed it on April 30, 1947; the Democrat had already brought the former Republican president back into public life to lead relief missions after World War II.

Which president signed the act authorizing Hoover Dam?

Calvin Coolidge signed the act in December 1928, while Herbert Hoover was president-elect; its $165 million price tag had helped stall the bill in Congress for six years.

Architect Gordon Kaufmann swapped the engineers' eagles and cornices on Hoover Dam for which style?

Art Deco replaced the ornament the engineers had planned: Kaufmann, an English-born Los Angeles architect, left the dam's curved face bare and smoothed its towers so the structure itself did the work.

What are the two bronze statues flanking Hoover Dam's flagpole called?

Winged Figures of the Republic were each cast in one continuous pour of bronze; their sculptor gave them 'the look of eagles' because, he wrote, building the dam belonged 'to the sagas of the daring'.

The terrazzo star map at Hoover Dam freezes the sky on which date?

The dam's dedication on September 30, 1935, is set into the floor so exactly that astronomers could work out the date from the star positions alone, even thousands of years from now.

Before politics, Hoover Dam's namesake made his fortune in which profession?

Mining engineer was Herbert Hoover's first career and made him a millionaire before 40, which is why the Interior Secretary who named the dam in 1930 called him 'the great engineer'.

The bridge that bypasses Hoover Dam is co-named for which former NFL player?

Pat Tillman walked away from a pro football career to enlist in the Army in 2002 and was killed in Afghanistan in 2004; the bridge's other namesake, Mike O'Callaghan, was a Nevada governor and Korean War veteran.

Lake Mead is named for Elwood Mead, who held what job?

Reclamation commissioner was Elwood Mead's post from 1924 until he died in office in January 1936; he had earlier drafted Wyoming's water laws, and the new lake was named in his honor.

What causes the white 'bathtub ring' visible around Lake Mead when the water is low?

Mineral deposits on once-submerged rock form the pale band, which marks where the water used to stand; the ring grows taller each year the lake falls, and by 2022 it showed clearly in satellite images.

Why do Hoover Dam's two ends, in different time zones, usually show the same time?

One state skips daylight saving: the dam's eastern side stays on Mountain Standard Time all year, which matches Pacific Daylight Time on the western side from March to November.

Herbert Hoover chaired the 1922 talks that produced the Colorado River Compact while holding which cabinet post?

Secretary of Commerce was Hoover's job when the seven river states deadlocked in Santa Fe; his fix, splitting the basin into upper and lower halves and leaving each state's share for later, became the Hoover compromise.

Which honor did Hoover Dam receive in 1985?

National Historic Landmark status came in 1985, the dam's 50th year; by then sales of its electricity had almost paid back the cost of building it, a debt cleared in 1987.

Hoover Dam's power plant was the world's largest hydroelectric station until which dam surpassed it in 1949?

Grand Coulee Dam in Washington State passed it in 1949 and now generates about five times as much electricity a year; Hoover's plant kept growing anyway, adding the last of its 17 main generators in 1961.

How did fresh concrete reach the rising blocks of Hoover Dam?

In buckets hung from cableways strung across the canyon, eight cubic yards at a time; crews of puddlers then stamped each load into its form.

What set off the August 1931 strike at Hoover Dam?

A cut in workers' wages set it off, with brutal heat and dangerous conditions already stoking anger; the contractor refused every demand, and the walkout collapsed within about a week.

What was the nickname of the riverbank squatters' camp where families waited for Hoover Dam jobs?

Ragtown, officially Williamsville, was the riverbank camp where families waited for dam jobs; in the summer of 1931 heat prostration killed 16 workers and riverside residents.

The Colorado River, tamed by Hoover Dam, naturally runs more than 1,400 miles to which body of water?

Gulf of California is where the river meets the sea, inside Mexico; that is why a 1944 treaty guarantees Mexico a share of the water the dams upstream hold back.

In their first fifty years, Hoover Dam's spillways ran only twice: in the 1983 floods and, in 1941, for which reason?

A planned test put water through the spillways in 1941; both that run and the 1983 floods tore into their concrete linings, which had to be repaired each time.

Which California dam overtook Hoover Dam in 1968 as the tallest in the United States?

Oroville Dam on the Feather River stands 770 feet, about 44 feet higher; but it is a mound of earth and rock, so Hoover remains the country's tallest concrete dam.

Which submerged Nevada town, drowned by Lake Mead in 1938, has resurfaced as the water level fell?

St. Thomas, a farming town founded by Mormon settlers, emptied as Lake Mead rose; one of its last residents paddled away from his doorstep in 1938, and the ruins have reappeared whenever the lake has dropped far enough.

Hoover Dam's memorial plaque says the men killed building it 'died to make' what bloom?

The desert: 'They died to make the desert bloom' opens the bronze plaque by Oskar J. W. Hansen, the Norwegian-born sculptor who won a national competition to design the dam's monument.

Interior Secretary Ray Lyman Wilbur announced the name Hoover Dam in 1930 at a ceremony starting work on which project?

The railroad line to the dam site began with a ceremonial spike Wilbur drove in September 1930; he said he was following a custom of naming great dams for presidents, and his boss was the one in office.

Denver artist Allen True based the terrazzo floor patterns inside Hoover Dam on designs from which cultures?

Southwestern tribes supplied the patterns: True adapted designs from objects such as an Acoma bowl and a Pima basket, favoring whirling motifs that echo the turbines spinning below.

Patrick Tierney, the last man killed building Hoover Dam, was which relative of a surveyor drowned scouting the site in 1922?

His son: surveyor J. G. Tierney drowned in the Colorado in 1922 while scouting dam sites, years before construction began, and Patrick fell from an intake tower in December 1935 as the work was ending.

Which dam downstream of Hoover is called the world's deepest, with most of its height buried below the riverbed?

Parker Dam hides 235 of its 320 feet below the old riverbed, where crews had to dig to reach bedrock; the Los Angeles-area water district that pumps from its lake paid for most of it.

How did Hoover Dam's builders move the Colorado River out of their way?

Through tunnels in the canyon walls: four of them, two on each side and each bored 56 feet across, carried the whole river around the site for about two years; two now serve as spillway outlets.

A Hoover Dam rope worker who swung crewmates around a jutting outcrop twice a day earned which nickname?

The Human Pendulum was Louis Fagan, who for weeks ferried a shift crew around a projecting outcrop one man at a time: each wrapped his legs around Fagan's waist and the pair leapt out over the canyon on one rope.

The concrete in Hoover Dam and its power plant could pave a 16-foot-wide highway from San Francisco to which city?

New York City: more than 4 million cubic yards went into the dam, power plant and outworks, enough for a road coast to coast, and crews placed the dam's own 3.25 million in under two years.