This stunning architectural and engineering marvel abounds in superlatives: the world's longest steel-arch span (1,700 feet) supports the 3,030-foot deck of the country's highest (876 feet) bridge east of the Mississippi. Put another way, the 555-foot Washington Monument would fit within the open arch, with 321 feet to spare. The American Bridge Division of USX (formerly United States Steel Corporation) won the contract to build the bridge with a bid of almost $34 million. Completed within four years, it is fabricated of the company's patented COR-TEN, the famous self-rusting steel that darkens with age and requires no painting. Although its awesome statistics imply a massive structure, the bridge is serenely graceful and delicate. It is best viewed from the National Park Service's Canyon Rim Visitor Center (
FY6) near its northern end, or from river level far below. The bridge, a segment of Appalachian Corridor L, is partially closed to vehicular traffic annually on the third Saturday in October for Bridge Day, a popular regional festival.