The Boulder Canyon Project in short
The dam in the Black Canyon grew out of the Boulder Canyon Project Act. President Calvin Coolidge signed it on 21 December 1928. The law authorized the dam, the All-American Canal and a division of the river's water among the states of the Lower Basin. Building began in 1931 and ended in 1936.
You can still see the construction story on site. Tour tickets include the exhibits, and our page for Hoover Dam tickets and tours lists the 2026 prices. For the measurements of the finished structure, see Hoover Dam facts.
Timeline of the Hoover Dam
The key dates from law to completion.
| Date | Event |
|---|---|
| 21 December 1928 | Boulder Canyon Project Act signed by President Coolidge |
| 11 March 1931 | Six Companies, Inc. wins the building contract |
| 6 June 1933 | First concrete placed |
| 29 May 1935 | Last concrete placed in the dam |
| 30 September 1935 | Dedication by President Franklin D. Roosevelt |
| 1 March 1936 | Formal acceptance of dam and powerplant |
The dedication and the formal acceptance are two separate dates, so a dam described as finished in 1935 and one described as finished in 1936 can both be right. The contractor was Six Companies, a consortium of western construction firms, with Frank T. Crowe in charge of the building work.
Our pick: a half-day dam tour
A simple guided trip from Las Vegas to see what the builders of the 1930s left behind.
Hand-picked tours, booked through GetYourGuide. Prices are indicative starting prices in US dollars (as of October 2026). Tap a tour for live availability and the current price in your currency.
Tours that bring the dam story to life
Guided visits, small-group trips from Las Vegas and combinations with Grand Canyon West, with live prices and availability.
The workers
About 21,000 men worked on the dam over the years. At any one time the average was 3,500, and the peak came in June 1934 with 5,218. Treat 21,000 as the total of men who worked on the dam, not as a count of everyone connected to the project.
The official count of industrial deaths at the site is 96. It covers falls, drownings and blasting accidents, and it leaves out deaths from heat, pneumonia or heart conditions. Other counts, such as 112, include earlier accidents during the survey work. Whichever number you meet, check what it includes. A common story says workers are buried in the concrete. That is not true: nobody is entombed in the dam.
Boulder Dam or Hoover Dam: the name
The structure has carried both names.
1930
Interior Secretary Wilbur proposed the name Hoover Dam.
May 1933
Interior Secretary Harold Ickes ordered the name Boulder Dam.
1947
Congress set Hoover Dam as the name for good.
Boulder City: the town the dam built
The federal government created Boulder City in the 1930s as a town for the dam workers. It stayed under federal control until 1959. Today the Historic District, listed in the National Register of Historic Places since 1983, is a stop on the way to or from the dam. Do not assume that interiors in the district are open or free, as that depends on each building.
If you plan a night nearby, read where to stay near Hoover Dam. For walks, the lake and the old railroad trail, see things to do near Hoover Dam.
Seeing the history on your visit
Where the story shows up on the ground.
Exhibits and the viewing deck
The tour tickets include the exhibits, the viewing deck and the Original Exhibit Building. The self-guided Visitor Center ticket is $15 per person in 2026. Children up to age 3 are free.
The powerplant
The Powerplant Tour takes you to the generators that the project was built for. The guide takes about 30 minutes, plus a 10-minute film.
The town
Boulder City has its own district to walk, a short drive from the dam. It makes a natural second stop for anyone interested in how the workers lived.
Hoover Dam history: frequently asked questions
When was Hoover Dam built?
Construction ran from 1931 to 1936. The first concrete went in on 6 June 1933, the last concrete in the dam on 29 May 1935, and President Roosevelt dedicated the dam on 30 September 1935.
How many people died building Hoover Dam?
The official count is 96 industrial deaths at the site. Counts such as 112 include earlier accidents during the survey work. Deaths from heat, pneumonia or heart conditions are not part of the 96.
Are there bodies in the concrete?
No. Nobody is buried in the dam.
Why was it called Boulder Dam?
Interior Secretary Harold Ickes ordered the name Boulder Dam in May 1933, after Wilbur had proposed Hoover Dam in 1930. Congress fixed the name Hoover Dam in 1947.
Who built Hoover Dam?
Six Companies, Inc., a consortium of western construction firms, won the contract on 11 March 1931. Frank T. Crowe led the building work.
Is this the official Hoover Dam website?
No. This is an independent guide, not the official site of Hoover Dam, the Bureau of Reclamation or the National Park Service, and not connected to any tour operator.