Nine hundred feet below our toes is the blue-green water of the Colorado River. A chilly wind pushes us just a little, enough to raise the adrenaline another notch. We’re standing atop plywood on the unfinished edge of the Hoover Dam Bypass Bridge, which is now only a part of a bridge, hanging out across Black Canyon from the edge of Nevada, reaching toward its mate rising out of the Arizona side. Someday, the two hunks of cement and steel will meet in the middle, the bridge will be complete, and an era will end, and another will begin.

The senses are alive up here—colors pop: turquoise sky and copper canyon walls; a beautiful, natural silence but for the occasional hum of a power tool hundreds of feet below, where men in hard hats systematically build the cement chunks of the bridge’s underlying arch. Every day they work on neither land nor water, but out in some indefinable stretch of space at the tip of what they are making. Some 2,000 workers are involved in this, but at the moment, I see eight men, quietly laboring on angled cement pillars steadied by steel cables attached to cranes planted in the ground on either side—a complicated engineering feat that happens with artistic ease. Thousands of passersby on the U.S. 93, which snakes below us and then across Hoover Dam a quarter mile north of the bridge, stop to watch the high-wire act. They snap photos and stare, jaws dropped in a shared sense of wonder. It’s absurd, and beautiful, and so over-the-top with metaphors for our place in time that I can think of nowhere else I’d rather stand at this moment.

When it’s finished, the 1,900-foot-long, 88-foot-wide bridge will hold four lanes of traffic—17,000 cars a day—and one pedestrian walkway. It will be the United States’ first concrete-steel composite arch bridge, in which the arch is cast in place over the river rather than precast and put into place. That means that before ever starting to build the bridge here, the construction team had to build temporary towers to support the growing arch using a cable system specifically designed for this project.

“You’re getting to see something pretty special right now,” says the bridge’s project manager, Dave Zanetell, the clean-cut, mid-40s employee of the Federal Highway Administration who brought me up here. I start to agree, but then notice that Zanetell is not referring to the awesome feat of engineering we are prematurely standing atop in hard hats and bright orange vests; instead his eyes are turned toward Hoover Dam—little Hoover Dam, wedged in the canyon walls far below us, plugging the Colorado, changing the course of history.

Seventy-eight years ago this month, another project manager, Frank Crowe, won the bid to construct what was then Boulder Dam. The nation was then in similar shambles, and the dam was meant to stop the rush of bad news, of depression, of joblessness; it was meant to conquer tributaries of problems with a big, bold, unprecedented solution: men would work, power would be distributed, the West would be irrigated; farms would rise, nature—the flood and drought of the environment and the ebb and flow of a people’s spirit—would be faced and fought, head on.

“March 4, 1931, began early for Frank Crowe,” writes Al M. Rocca in America’s Master Dam Builder. “Too excited to sleep, he was up early thumbing through some 300 sheets of calculations. It seemed too much for a single man to comprehend; over a hundred jobs, many of them occurring at the same time; thousands of man-hours toiling in the extreme temperatures of the Nevada desert. What if he had missed something? ...”

A bridge is a curious thing. Its metaphorical possibilities are endless—the idea of meeting halfway, of overcoming sometimes enormous divides, of linking entirely different ideas. The bridge is variously imagined as a fragile, temporary link, an escape route or the entryway to previously unreachable lands.

In our lives today—Las Vegas, Nevada, America, 21st century—spaces for bridges abound: between rich and poor, between the extreme right and the extreme left, between an industrial history and a virtual future. There’s an acute sense of the divide we are trying to cross right now in so many aspects of our lives: from dirty fuels to green living; from excessive consumerism to some mild pinch of accountability. There are questions Nevadans are grappling with that seem to have more gravity than in previous cycles—will we fund education, or won’t we? And questions for Americans—will we have health care, will we trust a free market, do we have any faith left in our way of life?

The Hoover Dam Bypass Bridge project will cost $240 million—spread among federal, Nevada and Arizona dollars, assuming none of those sources dry up—and is expected to be finished in 2010. Union contractors Obayashi Corporation and PSM Construction USA Inc. were given the construction contract as a joint-venture project.

The composite concrete deck arch bridge design was arrived at in order to meet specific challenges of the site: the aesthetics of the natural scenery and the juxtaposition with the dam; the speed at which it needed to be built (concrete and steel allow a faster construction than alternatives); economics.

Once the arch is complete and self-supporting—hopefully in September of this year—the cables will be removed, and the columns and deck will be built on top of the arch to make the roadway. Visitors will be allowed to walk on the dam side of the bridge to sight-see; but from the car, the dam will not be visible.

Deep inside the tunneling hallways of Hoover Dam, where the power plant is accessed and the workers check for structural damage and tourists march in lines through an American monument, you’d never know that thousands of cars a day use the ceiling of the dam as a bridge. Vehicles back up for miles on the two-lane highway in both directions—through Nevada and Arizona—waiting to cross the Colorado, which is now the pitifully shrunken Lake Mead north of the dam, and the ambling water in the Black Canyon to the south.

Down here inside the dam, cars are an afterthought. It’s a maze of dim passageways, steep staircases and the ghosts of 112 workers lost in the construction while canyon-blasting and cable-hanging and cement-pouring.

You have to give up a little control to go down into the dam, you have to trust that the thing works, that the engineering is solid. As we duck our heads and wend through what would be certain death if it were not, our guide tells us that every state in the nation contributed something to the dam’s construction—the nation had come together to recover. Steel, gravel, labor, tile—materials came from all over. He asks each of us where we are from and then tells us what our state contributed; and we feel a little more connected, not only to the dam but also to each other. As we take turns looking out a vent in the belly of the dam at the bridge growing over the canyon, there’s an odd sense of connection to it, too—a passing of the torch, perhaps. There’s a sense that we’re reviving one of America’s proudest moments here.

I am reminded that in 2001, after 9/11, we thought Hoover Dam might be the next target—a nightmare that would thwart power and water distribution to the American West as well as destroy a symbol of our strength. So we diverted trucks from U.S. 93 and began traffic stops to check smaller vehicles for explosives. And then, as the nation recovered from the World Trade Center attack, the plans to design and build carried on. In 2001, the post-environmental-studies go-ahead was given to design the Hoover Dam Bypass Bridge, which would be known also as the Colorado River Bridge, and ultimately as the Mike O’Callaghan-Pat Tillman Memorial Bridge—and which would allow those trucks, themselves a key part of the American economy, to stay on course.

And so it also happened all around the country—we moved forward. In a few years, we’d be betting on our own future earnings, rabidly building up real estate, constructing just to construct, increasingly tiptoeing out in some indefinable stretch of space at the tip of what we were making.

When the 300-foot-tall latticework cranes fell on September 15, 2006, pulling down the cables that helped stave off gravity, Zanetell was on his way out of his office in Colorado. It was a Friday evening around 5 o’clock. The guy on the telephone line was panicked. The Nevada North crane had toppled, and the cables were knocked down, pulling the Nevada South crane to the ground. Part of U.S. 93 had to be closed.

Zanetell was on-site in a few hours, and by 11 p.m., the team was gathered, the stakeholders were all represented, and three goals were set up:

1. Clean it up.

2. Figure out how it happened.

3. Keep on building.

The third one, says Zanetell, was most important, and got the most raised eyebrows—keep building while we sort this all out? He was leading a team of multiple contractors and subcontractors, an international crew speaking at least three languages, all housed in a camp of trailers on the Nevada side of the river. At first the accident was thought to be caused by an act of God—55 mph winds—but later, lawsuits would develop between parties.

For Zanetell, a guy raised in a family of miners, a guy who bucked the family history to pursue his engineering dream, the guy now in charge of a scenic and historic bridge construction project over Hoover Dam that commands a lot of attention, this can’t have been good. But he refuses to get down into the divisive muck when recollecting it.

“This is a team project, and the credit for this thing will go to the guys out there sweating every day, and the most important thing is not to divide them.” His task was to pull the team, fractured by a setback, back together and push on.

We knew it was coming in Vegas, maybe before a lot of the nation did. The feeling that we were tiptoeing in someone’s dream and didn’t want to wake them. How could it sustain itself? The skyscrapers of wealth, the luxury we built fast and loose—we sort of knew in our gut it was not engineered solidly. Somehow we suspected it was too good to be true; there was something amiss with the pace and the extravagance, the audacity of the economy we were building. We did with mostly luck what must be done with mostly skill; the mix was out of balance.

Nevada’s housing bubble burst, the unemployment level passed 9 percent, bankruptcies abounded, and the state government began looking at a historic shortfall. It’s a microcosm of the national situation; America slipped into an economic recession.

By the time the 2008 election arrived, we were broke, humbled. The nation was in need of a new plan to unify and go forward, a way to reconnect divergent views, a different route across a great divide. 

Every night for eight years—“except during hunting season”—Dave Zanetell has dreamed of the Hoover Dam bridge. “I’m a fretter,” he says with a big, confident smile. You barely believe he’s a fretter, because he practically oozes confidence, the leadership quality of a quarterback heading back out onto the field in any condition, whether ahead or behind, the right guy with the right team at the right time.

We’re standing out there on the bridge, the beauty of the day thrilling us both—Hoover Dam a solid forefather beneath us, the future rising, a piece yet to be put in place: the keystone of the arch.

An arch is a fundamental engineering structure. It goes back to Rome. It doesn’t really work—that is, it doesn’t actually support itself—until the last piece is put into place. Gravity is what cements it; you build the sides out from the canyon walls, but they aren’t stable until you get the keystone in place, and the pressure at the very highest, middle point cinches the structure, the force of gravity putting pressure in all the right places, holding the thing in its place. It’s kind of miraculous and magical to consider—the very part that looks like it would be most difficult to sustain, hanging out there way above ground in the middle with no support columns—is actually the vital component. The middle.

I’m considering how it all comes together as I stand here. High-wires, cables, columns of cement; risk-taking, strength, setbacks. Endurance. A pattern emerges and leads up to where we are now, both economically as a nation and in the construction of this bridge:  We clean up the debris, look out at the divide we want to cross and start to build again, tiptoeing out into nothingness. You have to trust that the thing works, that the engineering is solid.

I look down from 900 feet. Hoover Dam is to my left. It also relies on the arch structure—gravity pushes the sides of the dam into the canyon walls, solidifying its position right where it needs to be. I ask Zanetell about Frank Crowe: Does he see the parallels, even if the scale and the time are different?  Isn’t this a great time to be alive, seeing this span go up before our unbelieving eyes?

“I started reading about Frank Crowe and the construction of the dam again, but that’s when it got too overwhelming to think about,” he says. Sometimes, the gravity of a situation is best put off until the last stone is put into place.