Hoover Dam Is Dedicated

A Ceremony Above the Colorado

On September 30, 1935, President Franklin D. Roosevelt stood at Black Canyon to dedicate a vast concrete dam across the Colorado River. Thousands gathered in the desert heat for the ceremony. Known at the time as Boulder Dam, the structure represented years of planning, demanding labor, and an ambition to reshape the American Southwest.

A River of Opportunity and Risk

The Colorado River supplied water to a dry region, but its unpredictable flow also brought destructive floods. A dam could help control those floods, store water for farms and communities, and generate electricity. Before construction could begin, the states sharing the river had to confront difficult questions about how its water would be divided.

Building Through the Great Depression

Construction began in 1931, when the Great Depression had left many Americans searching for work. Workers excavated diversion tunnels to carry the river around the construction site, cleared loose rock from the canyon walls, and prepared the foundations. Concrete was then placed in interlocking blocks, with cooling pipes helping remove the heat produced as it hardened.

The Human Cost

Behind the monumental structure were workers and families facing intense desert heat and dangerous conditions. The project provided desperately needed employment, but construction also cost lives. Its history includes both extraordinary engineering and the sacrifices of the people who made it possible.

Dedicated Before Every Task Was Finished

Roosevelt’s dedication marked a major milestone, but it did not mean every part of the project was already operating. Work continued after the ceremony, and electricity generation began in 1936. The reservoir behind the dam, Lake Mead, gradually became a vital store of water for the Southwest.

A Landmark with Two Names

The dam’s name became entangled in politics. Although the name Hoover Dam had been announced before construction, the Roosevelt administration used Boulder Dam. In 1947, Congress officially restored the name Hoover Dam, honoring President Herbert Hoover’s role in advancing the project.

An Enduring Symbol

Hoover Dam became a defining landmark of the American Southwest. Its immense curved wall remains a striking example of what engineers and workers accomplished in a difficult era. The dedication on September 30, 1935, celebrated a structure that would influence the region’s water supply, electricity, and development for generations.

Timeline

1928-12-21 — The Boulder Canyon Project Act becomes law, authorizing the project.

1931 — Construction of the dam begins.

1935-09-30 — President Franklin D. Roosevelt dedicates the dam, then called Boulder Dam.

1936 — The power plant begins generating electricity.

1947 — Congress officially restores the name Hoover Dam.

Location

Black Canyon, Nevada–Arizona border, United States