Boulder City in Clark County, Nevada — The American Mountains (Southwest)
Choose the Site for Crossing & Bridge
Journeys & Heroes
Photographed by Sandra Tidwell Hughes, September 9, 2025
1. Choose the Site for Crossing & Bridge Marker
Best Crossing Site
Seeking the best new bridge site was one of the first major decisions in bypassing the river crossing atop Hoover Dam.
The Project Management Team (PMT) identified 13 alternative routes early in the project. These crossings ranged from as far south as Laughlin to as far north as Lake Mead. Only three crossing alternatives near Hoover Dam deserved further study:
1) Promontory Point crossing Lake Mead 1,000 feet north of the dam;
2) Sugarloaf Mountain, crossing Black Canyon 1,500 feet south of the dam;
3) Gold Strike Canyon, crossing the Colorado River about 4,000 feet south and out of sight of the dam.
The PMT compared the three alternatives to determine the best balance of highway approach and river crossing location. The Sugarloaf Mountain Alternative proved to be the best. Its site conditions allowed for optimal traffic flow, straightforward construction, and minimal potential for environmental impact.
Best Bridge Type
Then, the project Team selected the Deck Arch design as the best of the five possible bridge types for the Colorado River crossing.
The Design Advisory Panel (DAP) also recommended guidelines for the new bridge design. They called for the design excellence of today to honor the achievements of the Hoover Dam's designers in their day. This goal guided the design team's work through the further study of six deck arch alternatives. The final decision was to build a unique structure combining a modern steel superstructure with a long-span concrete arch to complement the historic Hoover Dam.
The bridge design is distinctive not only for the setting and length of the arch span, but also for the combined use of steel and concrete to optimize construction and structural performance.
Topics. This historical marker is listed in this topic list: Bridges &
this page online
Location. 36° 0.882′ N, 114° 44.675′ W. Marker is in Boulder City, Nevada, in Clark County. It is on Hoover Dam Access Road. Touch for map. Marker is at or near this postal address: 81 Hoover Dam Access Road, Boulder City NV 89005, United States of America. Touch for directions.
Regionally, this marker is in Nevada’s Colorado River Valley, 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 Mexicos Alta California.
Other nearby markers. At least 8 other markers are within walking distance of this marker: Span The Gap with Cables 7 Arch (here, next to this marker); Protecting the Place of Nature & History (here, next to this marker); Lay the Path with Cut & Fill (here, next to this marker); Clear the Way of Switchyard & Towers (here, next to this marker); Design the Dream with Science & Art (here, next to this marker); Enjoying the Ride with
Photographed by Sandra Hughes Tidwell, September 9, 2025
2. Choose the Site for Crossing & Bridge Marker
Credits. This page was last revised on October 3, 2025. It was originally submitted on September 28, 2025, by Sandra Hughes Tidwell of Killen, Alabama, USA. This page has been viewed 76 times since then and 22 times this year. Photos: 1. submitted on September 29, 2025, by Sandra Hughes Tidwell of Killen, Alabama, USA. 2. submitted on September 28, 2025, by Sandra Hughes Tidwell of Killen, Alabama, USA. • Andrew Ruppenstein was the editor who published this page.
