I'd come to San Francisco to work out whether the Golden Gate Bridge, named for the strait that connects the San Francisco Bay to the Pacific Ocean, might not be the end of America—its final border, the end of the West. This notion follows if you consider the beginning of the country, naturally, to be the Statue of Liberty. If the country has a beginning and an end, these are surely the two spots.

Yet for an immigrant from the Pacific Rim, surely the Golden Gate is where the country begins, not finishes. Joan Didion knew this, writing in 1982, “The Golden Gate Bridge, referring as it does to both the infinite and technology, suggests, to the Californian, a quite complex representation of land's end, and also of its beginning.” So the idea is not without problems. All the same, there is clearly some historical sense to the simple metaphor of the West as end, keeping in mind that the American movement westward through the initial stages of the nation's development is a historical fact, not a point of view. There is a tradition of the West as the nation's vanguard, the place of youth and revolution, and inasmuch as the bridge represents the place—who, please, goes to San Francisco and buys a postcard of Coit Tower?—the bridge thus also represents the frontier, the furthest reach, the edge.

The next problem in fixing a beginning at the Statue of Liberty and an end at the bridge is that it makes an uneven pair of anchors. The statue is only a monument, and the bridge, 1.7 miles long, is an essential and utilitarian piece of infrastructure as much as it is an icon. It can't just stand there untouched, but is used every day: Indeed, about 40 million vehicles cross the bridge annually, coming down from Marin County into the city and vice versa. That is to say, the bridge is difficult to make stand still as a simple icon.

The bridge is now in the middle of a $471 million seismic retrofit aimed at making it as safe and strong as possible—that is, better able to move with and dissipate seismic forces—without changing its appearance at all. Phase 1, shoring up the North (Marin) Viaduct, began in 1997 and finished in 2002; the second phase, strengthening the South (San Francisco) Viaduct, finished earlier this year; and the third phase, retrofitting the main span, is expected to continue through 2012. Engineers have replaced all the steel towers, which are up to 150 feet tall, below the south and north approaches to the central span. Pylons and anchorage housing have been strengthened, dampers and stiffeners and bracing installed. “It's 10 times stronger, but the public doesn't see any difference,” I was told by Denis Mulligan, chief engineer for the Golden Gate Bridge, Highway and Transportation District.