Hoover Dam
Interesting facts
- The first recorded death on the project, surveyor J. G. Tierney, drowned on 20 December 1922; his son Patrick died there on 20 December 1935.
- The dam is about 200 metres thick at its base, tapering to just 14 metres at the top, enough to carry a highway.
- Before the dam could rise, the Colorado River was diverted through four tunnels 17 metres across, together more than 5 kilometres long.
- In the summer of 1931, with daytime highs averaging around 49 °C, sixteen workers and nearby residents died of heat prostration in a single month.
- 'High scalers' dangled on ropes down the canyon walls, prying off loose rock with jackhammers and dynamite before pouring could start.
- Six Companies won the contract with a bid of about $48.9 million, within $24,000 of the government's own estimate.
- At its peak in July 1934 the project employed 5,251 workers.
- Lake Mead, the reservoir behind it, can hold about 35 cubic kilometres of water, making it one of the largest reservoirs in the United States.
- The river was turned into the Arizona tunnels on 13 November 1932, letting crews excavate the dry riverbed.
Why it is worth it
Hoover Dam plugs the Black Canyon of the Colorado River on the border between Nevada and Arizona, a curved wall of concrete standing 726 feet (about 221 metres) from its foundation rock to the roadway on its crest. Built between 1931 and 1936 during the Great Depression, it created Lake Mead and was, at the time, a concrete structure of unprecedented size: some 3.25 million cubic yards went into the dam alone. It was handed to the federal government in March 1936, more than two years ahead of schedule.
The engineering problems were enormous. Poured in one mass, the concrete would have taken over a century to cool and would have cracked as it did; instead it was placed in interlocking blocks threaded with cooling pipes carrying chilled water. The human cost was heavy too. The official list names 112 deaths connected with the project, and dozens more deaths recorded as pneumonia among men who worked in the exhaust-choked diversion tunnels were never counted. The popular story of workers entombed in the concrete is a myth — each pour raised a block by only a few centimetres.
What surprises many visitors is how beautiful the dam is. The architect Gordon B. Kaufmann gave the plain engineering an Art Deco skin: streamlined turrets on the downstream face and intake towers with clocks showing Nevada and Arizona time. The artist Allen Tupper True designed floors and walls with motifs drawn from Navajo and Pueblo art. On the Nevada side, Oskar Hansen's two 9-metre bronze Winged Figures of the Republic flank a flagpole above a terrazzo star map fixing the sky at the moment President Roosevelt dedicated the dam on 30 September 1935.
The dam was named for Herbert Hoover, then called Boulder Dam for fourteen years, and restored to Hoover by Congress in 1947. Through traffic moved in 2010 to the Mike O'Callaghan–Pat Tillman Memorial Bridge, 460 metres downstream, and from which the whole curve of the dam can be seen. The crest road is still open to visitors driving from the Nevada side to the parking on the Arizona side.
Getting there
Boulder City, the town built to house the dam's workers, is about 10 km away; Las Vegas lies about 48 km to the northwest. Boulder City Municipal Airport (BLD), about 13 km away, is a small regional field. The dam is reached by car via US 93 and the access road on the Nevada side.
On these lists
36.01583, -114.73778per Wikidata