Near Boulder City in Clark County, Nevada — The American Mountains (Southwest)

Tunnel Construction

Photographed by Tom Bosse, July 20, 2024

1. Tunnel Construction Marker

Inscription. The Six Companies, Inc. crew blasted tunnels to divert water, faced carbon monoxide-chocked tunnels and worked with jackhammers from heights of 700 feet. Casualties resulted from falling equipment, rocks and workers. This view shows the interior of one of the tunnels through which the Colorado River was to be diverted around the Hoover Dam site, April 18, 1932.

Top
Shown is a ‘high scaler’ going over the side on the Arizona rim of Black Canyon. Note the safety bels and rope. 11/16/1932 Digital Image WASH-No-1449 from Bureau of Reclamation.

Middle
Completed tunnel lining at intake portal of Diversion Tunnel No. 4 at Hoover Dam, view looking toward entrance. Pressure grouting jumbo seen in operation. 10/26/1932 Digital Image WASH-No-14209 from Bureau of Reclamation.

Bottom
Hoover Dam Plan, 1930 Digital Image from: https://commons.wikimedia.org.

Topics. This historical marker is listed in these topic lists: Bridges & Viaducts • Industry & Commerce. A significant historical date for this entry is April 18, 1932.

Location. 35° 59.668′ N, 114° 47.954′ W. Marker is near Boulder City, Nevada, in Clark County. It is on Interstate 11, on the right when traveling north. Marker is located at the Robert L. Mendenhall Scenic Overlook. Touch for map. Marker is in this post office area: Boulder City NV 89005, United States of America. Touch for directions.

Regionally, this marker is in the Mojave Desert

and in Greater Las Vegas.

It is also in the American Southwest

and in the Mountain West.

Globally, it is in North America,

the Western Hemisphere,

the Western World,

and the Anglosphere.

Historically, it finds itself in what was once New Spain

and also Mexico’s Alta California.

Other nearby markers.

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At least 8 other markers are within walking distance of this marker: Boulder City (here, next to this marker); Origin of the Dam (here, next to this marker); Boulder Dam! No! (here, next to this marker); Lake Mead National Recreation Area (here, next to this marker); The Colorado River (here, next to this marker); Dam Completion (here, next to this marker); Robert L. Mendenhall Scenic Overlook Obelisk (a few steps from this marker); Interstate 11 Project Team (a few steps from this marker). Touch for a list and map of all markers in Boulder City.

Photographed by Tom Bosse, July 20, 2024

2. Tunnel Construction Marker

Photographed by Tom Bosse, July 20, 2024

3. Tunnel Construction Marker

Tunnel Inside Hoover Dam image. Click for full size.

Photographed by Tom Bosse, July 20, 2024

4. Tunnel Inside Hoover Dam

Photographed by Tom Bosse, July 20, 2024

5. Hoover Dam

Credits. This page was last revised on October 4, 2024. It was originally submitted on August 18, 2024, by Tom Bosse of Jefferson City, Tennessee. This page has been viewed 163 times since then and 25 times this year. Photos: 1, 2, 3, 4, 5. submitted on August 18, 2024, by Tom Bosse of Jefferson City, Tennessee. • Bill Pfingsten was the editor who published this page.