An overview of Hoover Dam construction history with photos. Hoover Dam was a federal project since the river’s basin covered several states and the river enters Mexico. These seven states of the Colorado basin were California, Nevada, Arizona, Utah, New Mexico, Colorado and Wyoming. After the dam was authorized; and before the dam could be built, thousands of workers came to southern Nevada to work on the dam. Workers had to be housed; Six Companies Inc. built Boulder City, Nevada for this proposes beside Las Vegas which grew considerably. Prior to constructing the dam, the wild Colorado River had to be diverted away from the construction site (Black Canyon). To do this, four blasted tunnels were carved right through the canyon walls on both the Arizona and Nevada sides beginning in 1931. Two temporary enclosure dams were constructed to prevent flooding of water into the area where men would be building the dam. The Hoover Dam and the installation of vertical columns of blocks for arch structure of the dam began. Hoover Dam was constructed between 1931 and 1936. Today, the Hoover Dam is the second highest dam in the state and the 18th highest in the world and it is a major tourist attraction as it is close to Las Vegas .

Construction History of Hoover Dam _1 Construction History of Hoover Dam _3

Construction History of Hoover Dam _4

1-This is a night view of the Hoover Dam.

Construction History of Hoover Dam _1

2-The vision for a dam on the Colorado River began as early as 1902 .This was the site of one of the greatest federal engineering project of its time, the place where Hoover Dam would be constructed, is shown Sept. 19, 1930. Hoover Dam, the biggest dam project in the world when it was completed.

Construction History of Hoover Dam _2

3-A lake covering 227 miles will form the 30,500,000 acre foot reservoir to a depth of 10 feet when full from Hoover Dam when completed. The flat top lone mountain in the center of the photograph will submerged after the completion of the project to be an island 14 feet above water.

Hoover Dam Construction 1932

4-An aerial view of the becoming Hoover dam project region on March 4, 1931.

hydroelectric power

5-It is here that Hoover Dam project would rise. The diverted water of the Colorado is flowing from the mouths of the tunnels.

hydroelectric power

6-A steel bucket holding eight cubic yards dumps the first concrete was poured in June 1933 on the floor of Black Canyon in Boulder City, Nev., June 9, 1933.


7-The Colorado River was diverted during constructed of Hoover Dam in the period of 1932-1934. This view shows the interior of one of the four 50-foot-wide tunnels, drilled through the solid rock walls of the Black Canyon through which the Colorado River will be diverted around the Hoover Dam site two drilled through the canyon walls on each side of the river. The largest of these tunnels was three miles long and had a diameter of three miles.

Construction History of Hoover Dam _1


Construction History of Hoover Dam _22


Construction History of Hoover Dam _23




Construction History of Hoover Dam _25


Construction History of Hoover Dam _26


Hoover Dam Construction


8-Jumbo Rig; is an engineering construction technology equipment provided to speed up the Hoover Dam’s tunnel drilling process. Built on the back of a 10-ton truck, 24 to 30 drills could be operated at once.

Construction History of Hoover Dam-8-

9-Placing concrete in the sidewall of the Nevada spillway June 1933.

Construction History of Hoover Dam-9-

10-This undated view, looking upstream through the Black Canyon would be thick concrete forms at the base of the Hoover Dam and thin near the top.



11-The dam was built in 215 vertical columns of concrete blocks because of its contraction after cooling. These concrete blocks were varied in size from about 60 feet square to about 25 feet square from the upstream face to the downstream face. After the concrete was cooled, a cement and water mixture was forced into the spaces created between the columns to form a monolithic (one-piece) structure.

Construction History of Hoover Dam _3


Construction History of Hoover Dam _2


Construction History of Hoover Dam _4


30 seconds time lapse video.

12-Working night and day; has pushed the schedule ahead for months.

Hoover Dam Construction

13-To build Hoover Dam an earth fill dam across the Colorado River was built to force its water into two fifty-foot diversion tunnels on the Arizona canyon wall using a constant stream of large trucks dumping fifty tons of soil a minute.


14-The core of the dam, near Boulder City made of immense concrete blocks lifted from the base of Black Canyon’s bedrock floor Nev., Aug. 12, 1933.


15-This is an aerial view of one of the four 338 feet (103 meter) high Intake Towers that will stand in the deep waters of Lake Mead behind Hoover Dam, Aug. 9, 1934, two on each side.


Construction History of Hoover Dam _5

Construction History of Hoover Dam _4

16-Construction of a retaining wall that gives support to the road which will be at the top of the dam itself Jan. 9, 1932.


17-Another view of the Hoover Dam from upstream as construction continued building the 215 vertical columns of concrete blocks, Nev., Feb. 1, 1935
The crack in the upper center of the dam is a space left open will be filled with concrete after the cooling process as work progresses.


18- One of the 4 tunnels which were used to divert the Colorado River ready to be closed on Feb. 1, 1935, as a step before filling the huge reservoir.

Hoover Dam Construction 1935

19-This general view of Black Canyon on the Colorado River, looking upstream toward the site of Hoover Dam, shows a temporary steel suspension bridge in the foreground and portals of the four 56-foot-diameter diversion tunnel bores which will divert the Colorado River’s flow around the Hoover Dam while it is under construction, March 12, 1932. Their combined length was nearly 16,000 feet (more than three miles).

Hoover Dam Construction 1932

20-Construction of The cement forms for the two power plants.


21-A closer look at the Construction of the cement forms for the two power plants.


22-Construction of the 13 feet diameter needle valves of the power plant.


23- (1935)* – Hoover Dam power plants view getting close to completion.


24An over view shows a highway on the crest of the Hoover Dam, aka Boulder Dam, which will provide an easy route between Las Vegas, Nev., and Kingman, Arizona July 16, 1935.


25-The rarely-seen upstream face of Hoover Dam, May 1935.

Construction History of Hoover Dam-26

26- workers painting the slanted wall of riveted-steel plates on the Hoover Dam spillway. Photo dated between 1936 and 1946.

Construction History of Hoover Dam-27

27- (1935)* – Hoover Dam close to completion. Water can already be seen at the base of the dam.

Construction History of Hoover Dam-26

28-The Hoover Dam is nearing completion Aug. 28, 1934.

Hoover Dam Construction 1934

29- The Hoover Dam was on its finishing touches on Aug. 12, 1931.


This is the 3500 horsepower generator in the foreground, on September 11, 1936 created the first power from the dam in Boulder City. `

Hoover Dam Construction


31- This is the 3500 horsepower generator in the foreground, on September 11, 1936 created the first power from the dam in Boulder City. `

Construction History of Hoover Dam-32

32 A view of the Hoover Dam1935

Hoover Dam

FDR At Boulder Dam 1935

33- An aerial view of the Hoover Dam of the Boulder Canyon project on March 13, 1936


34-This is the high-voltage switching yard in the Department of the Interior at Boulder Dam, at night April 27, 1937.

hydroelectric power

35-(1934) – Looking down at the construction of one of the Nevada intake towers that will rise 395 feet into the air. These towers permit and control flow of water into tunnels and then to huge generators in the power turbines below the 727-foot dam.
Hoover Dam Construction

Hoover Dam Construction

Construction History of Hoover Dam-

36- These six 82, 500-vollite generator in the world’s biggest power plant in the Nevada wing of the power house at Boulder Dam Feb. 7, 1939 can start electricity over the world’s longest power transmission line ( 365 miles to Los Angeles). Production at that time was approximately one-third of the ultimate capacity. (AP Photo)

Hoover Dam Construction

37- An aerial view over Lake Mead and Boulder Hoover Dam, July 13, 1948.
(AP Photo)

hydroelectric power

38- Night view of Hoover Dam and Mead Lake at Dusk shows the roadway over the dam top illuminated and the candles atop the intake towers, Sept. 20, 1950. (AP Photo)

Hoover Dam Construction

39 This magnificent man-made Hoover Dam known as one of the world’s largest electrical power plants is one of this century’s outstanding triumphs of engineering and construction. Hoover Dam provides a variety of pleasures for visiting vacationers thus became a favorite vacation playground. Lake Mead, stretching above the dam for 115 miles which is the largest reservoir in the United States offers excellent fishing all year and is a perfect spot for boating, swimming and other water sports through the long summer season.

Hoover Dam Construction

Hoover Dam Construction

Lake Mead near the 395-foot-tall intake towers of Hoover Dam. Through these towers flows the water which operates the huge generators in the powerhouse below the 727-foot dam April 14, 1938.

Hoover Dam Construction

41-Spectators watch from bridge over the Arizona as Boulder Dam has been opened for an indefinite period to empty overflowing for first time in the history of the dam, August 6, 1941, and pours 15,000 cubic feet per minute from record level of Lake Mead into Colorado River behind the dam. The upper part of Lake Mead will be in preparation for re-filling floods next spring.

Hoover Dam Construction

Hoover Dam Construction

Hoover Dam Construction

42- The mighty man-made falls of the Colorado River Millions of gallons of water gush from bypass tunnels from the six outlets while wide open.


43-An aerial view shows the Mike O’Callaghan-Pat Tillman Memorial Bridge 1,900-foot-long structure sits 890 feet above the Colorado River and bypassing the Hoover Dam October 26, 2010.The bypass project was constructed to relieve vehicle traffic on the Hoover Dam.

Hoover Dam Bypass Bridge Project Complete

44-44-(October 9, 1936)* – The beacon light placed on the top of Los Angeles City Hall is lighted when power arrived from Hoover Dam , the street became ablaze with light tens of thousands of people jammed the parade route on Broadway on that night when the first Hoover power streaked 266 miles from the power plant to Los Angeles. .




Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.