Tunkhannock Creek Viaduct (also known as the Nicholson Bridge and the Tunkhannock Viaduct) is a concrete deck arch bridge that spans the Tunkhannock Creek in Nicholson, Pennsylvania, in the United States. Measuring 2,375 feet (724 m) long and towering 240 feet (73 m) when measured from the creek bed (300 feet (91 m) from bedrock), it was the largest concrete structure in the world when completed in 1915 and still merited "the title of largest concrete bridge in America, if not the world" 50 years later.[4] Built by the Delaware, Lackawanna and Western Railroad (DL&W), the bridge is owned today by the Canadian Pacific Railway and is used daily for regular through freight service, including those of the Norfolk Southern.