Hoover Dam, Arizona-Nevada

Steven Dutch, Professor Emeritus, Natural and Applied Sciences, Universityof Wisconsin - Green Bay

Hoover Dam was originally planned to be built across Boulder Canyon (top right), hence the former name for the dam, Boulder Dam. At some point planners realized that building in the present location (actually called Black Canyon) would result in a larger lake with no increase in cost.

The contour map above gives only a faint hint of the chaotic landscape south of the dam.

The dam and its environs.

Comparison of a dam at Boulder Canyon (top) with the actual dam. Not only does the present dam achieve the same water level but it may actually require less material.

Pictures below were taken in April 2001, June 2002 and November 2005, accounting for the differences in lighting and water conditions.

Memorial plaque honoring Herbert Hoover. The dam was originally to have been built across Boulder Canyon some distance to the north. The site was changed to the present location to create a bigger reservoir but even though the canyon here is Black Canyon, the project was still known as Boulder Dam. It was named Hoover Dam when the project was dedicated in 1930. In 1933 the Roosevelt Administration changed the name to Boulder Dam, which it remained until 1947, when it was changed back to Hoover Dam.
Bench mark on the dam.
Below left: Outlet of the dam. Other photos below: looking downstream from the dam.
Left and below: Earth in the Precambrian. The terrain immediately south of the dam is one of the most hostile and sinister looking landscapes I know of. Some types of volcanic rocks, especially rhyolites, weather to this chaotic appearance in desert conditions. We can see where the name Black Canyon came from.
View of the dam. The old approach to the dam offered few opportunities for viewing or photography, all of them pretty dangerous. A bypass had been planned for some time before 9-11, because of concerns about dangerous cargo crossing the dam. Recently construction began on a bridge over the canyon south of the dam.
Left: support tower for cables crossing the canyon.

Below: views of the dam face.

Left: spillway behind the dam

Below left: spillway intake


Above: looking upriver toward Lake Mead. Below: the algal blooms in these pictures plus the 1930's architecture calls to mind the Emerald City of Oz.
Above: views from the Arizona overlook. Below: the surroundings of the dam.
Left and below: the volcanic rocks that abut the dam are intruded and faulted.
Below: the canyon south of the dam is pretty much inaccessible, but can be seen from a distance. Note the cuestas defined by lava flows.

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Created 15 January 2007, Last Update 06 June 2020