Bear Mountain Bridge: 100 Years of the Suspension Bridge That Inspires Modern Engineering

Heading up the Hudson River, just over an hour’s drive from Manhattan, you enter Bear Mountain State Park, a natural oasis among the rugged mountains that rise along the river’s western shore. The landscape feels a world away from the hustle and bustle of New York City—until you reach the centennial Bear Mountain Bridge, a striking suspension bridge over the water with a design reminiscent of the Big Apple’s most iconic bridges, from the Brooklyn Bridge to the Manhattan Bridge. It too is a symbol of pioneering engineering.

Opened to road traffic on November 26, 1924, the Bear Mountain Bridge set modern engineering standards that ushered in a golden era of bridge construction over North American rivers. At the time of its construction, it boasted the world’s longest suspended main span (1,632 feet, or 497 meters), ten meters longer than that of the Williamsburg Bridge, built two decades earlier over the East River in New York.

That was enough to earn a record it held for 19 months, until the Benjamin Franklin Bridge—designed using similar engineering principles—took the title in 1926. That suspension bridge remains a primary artery connecting Pennsylvania and New Jersey across the Delaware River.

For the construction of the Bear Mountain Bridge, which features two towers standing 360 feet (110 meters) tall and a deck height of 155 feet (47 meters) above the water, innovative solutions were adopted that influenced several major suspension bridges built in the following years, such as New York’s George Washington Bridge and San Francisco’s Golden Gate.

The Bear Mountain Bridge was the first American suspension bridge with a concrete deck and implemented new anchoring techniques embedded in rock, as well as the assembly of two 2,600-foot-long (792-meter) cables, each 45 cm in diameter and made up of 7,452 galvanized wires.

Since then, much has changed, and modern engineering has shattered previous records for suspension bridge spans, now four times longer than before. Today, the longest suspension bridge in the world is in Turkey: the 1915 Çanakkale Bridge with a span of 2,023 meters (6,637 feet). Turkey and the Bosphorus strait have become global training grounds for building large-scale bridges.

Webuild Group, which participated in constructing the Second and Third Bosphorus Bridges, also built Romania’s Braila Bridge on the Danube —the second longest in continental Europe—and signed its name to other major bridges around the world, including the Long Beach International Gateway in California, which replaced the old Gerald Desmond Bridge and links the Port of Long Beach to the mainland, a strategic piece of infrastructure for freight transport across the United States.

Sometimes design, technical features, and modern engineering mega projects alone aren’t enough to fully convey the greatness of these structures. Many, because of the role they have played and continue to play, have become symbols for the countries and communities they serve.

This is the case of the Bear Mountain Bridge, which has been declared a Historic Landmark and is now part of America’s cultural heritage. These honors also aim to acknowledge the extraordinary effort behind such major projects—an effort often reflective of the times and one that perfectly captures the spirit of the Roaring Twenties.

According to accounts from that period, the construction of the Bear Mountain Bridge was among the most complex of its time, largely due to the area’s geology. The terrain was almost entirely granite, and 70% of the material had to be drilled and blasted. These operations were carried out without disrupting service on the New York Central Railroad, which ran directly beneath the new bridge’s anchors.

As with many major infrastructure stories, where the risk is highest, engineering has found solutions to build ever more spectacular, safe, and long-lasting hanging bridges. And in the case of the Bear Mountain Bridge, more cost-effective too—crossing it cost $2.30 in 1925, while today, a century after its inauguration, the toll is electronic and costs $1.65 per vehicle.