Dam of its scale had ever been attempted; on completion, it was the largest masonry dam in the world. The Hoover Dam is a massive concrete arch-gravity dam, constructed in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada between 1931 and 1936 during the Great Depression. In 1928, Congress authorized the project to build a dam that would control floods, provide irrigation water and produce hydroelectric power. The winning bid to build the dam was submitted by a consortium called Six Companies, Inc. Such a large concrete structure had never been
Course of the Colorado River load. The area around the confluence is dominated geographically by Navajo Mountain which rises over a mile (1.6 km) above the surrounding landscape, which is part of the Navajo Nation. Rainbow Bridge, one of the highest natural bridges in the world, is located at the tip of an arm of Lake Powell at the foot of Navajo Mountain. Glen Canyon Dam, which creates Lake Powell, is situated in the town of Page in northern Arizona only about by river from the Utah border. The dam impounds the Colorado primarily for hydroelectricity generation. In front of the dam the Glen Canyon