Upper Hack Lift is a lift bridge carrying the New Jersey Transit Main Line across the Hackensack River at mile 6.9 between Secaucus, New Jersey and Lyndhurst.It was built by the Delaware, Lackawanna and Western Railroad in 1958 and completed in March 1959 to serve the Boonton Line and replaced an older swing span from 1901 on the site, which had been damaged by shifting currents.