Today In History logo TIH
The first hydroelectric generator at Boulder Dam, later renamed Hoover Dam, bega
Featured Event 1936 Event

October 9

Hoover Dam Powers Up: Electricity for the Southwest

The first hydroelectric generator at Boulder Dam, later renamed Hoover Dam, began producing power on October 9, 1936, sending electricity 266 miles across the desert to Los Angeles through the largest transmission line ever built. The dam itself was an engineering marvel: 726 feet high, containing 3.25 million cubic yards of concrete that would take 125 years to cool naturally. Engineers embedded cooling pipes throughout the structure to speed the process. Construction had killed 96 workers during the five-year build. The cheap electricity it produced powered the aluminum smelters, aircraft factories, and military installations that fueled Southern California's wartime boom. Las Vegas, 30 miles away, grew from a railroad stop to a city on Hoover Dam power. Lake Mead behind the dam became America's largest reservoir.

October 9, 1936

90 years ago

Key Figures & Places

What Else Happened on October 9

Talk to History

Have a conversation with historical figures who witnessed this era. Ask questions, explore perspectives, and bring history to life.

Start Talking