5 Powerful Facts To Know About The Hoover Dam

On July 7, 1930, construction of the Hoover Dam began outside of Las Vegas, Nevada. It was the largest dam of its time, as well as one of the largest man-made structures in the world. Here are five powerful facts you probably didn't know about the Hoover Dam...


It Once Was The Earth’s Tallest Dam Rising 726.4 feet, Hoover Dam was the world’s tallest dam when it was built in the 1930s. These days, it’s the second-tallest dam in the U.S., having been surpassed by the 770-foot-high Oroville Dam in Northern California in 1968. The globe’s tallest dam is the 1,001-foot-high Jinping-I Dam in Liangshan, Sichuan, China, which became operational in 2013.

It Contains Enough Concrete To Wrap Around The Earth Imagine a four-foot-wide sidewalk wrapped completely around the Earth at the equator. That’s a lot of concrete! That’s how much concrete it took to build the Hoover Dam. It’s amazing when you think about it. The dam is 726 feet tall and 1,244 feet long. That’s almost a quarter of a mile. At its base, the dam is a whopping 660 feet thick. That’s longer than two football fields stretched end-to-end!  Additionally, the dam required about five million barrels of cement, nearly equaling the total quantity of cement utilized by the The Bureau of Reclamation in its previous 27 years of existence.


Building Hoover Dam Created An Entire City Speaking of places named Boulder, you may not know that Nevada’s Boulder City didn’t exist before the Hoover Dam project. In fact, the city was built in 1930 solely to house the 5,000 workers employed to build the dam. Boulder City was constructed on federal land and had no local mayor or other elected officials. Oddly enough, the entire city was managed by an employee of the U.S. Bureau of Reclamation. This person had the power to institute rules as he saw fit. Some of Boulder City’s early statutes even banned gambling and the consumption of alcohol. It wasn’t until 1960, thirty years after the city’s initial construction, that the federal government surrendered control, and Boulder City was officially incorporated.


As Many As 138 Workers Died During Construction Hoover Dam was built between 1931 and 1936, and those five years were not without disaster. Reports from the construction site list 96 deaths due to accidents. In addition, 42 workers were reported to have died from illnesses while the dam was being built. However, today some historians believe that it was exposure to carbon monoxide in construction tunnels resulting in carbon monoxide poisoning, which actually caused these additional deaths.

The Nazis Plotted To Blow Up Hoover Dam During WWII In November 1939, U.S. officials learned of a Nazi plan to blow up Hoover Dam. Destroying Hoover Dam would have had the disastrous effect of cutting off critical electrical power to southern California’s airplane manufacturing industry. To combat further attempts on the dam, U.S. authorities imposed restrictions on boats allowed into Black Canyon and employees who worked at the dam. Following the December 1941 attack on Pearl Harbor and America’s entry into World War II, Hoover Dam was closed to all visitors until the war ended in 1945.