Colby Cut (also known as Roseville Cut) is one of a number of cuts on the Lackawanna Cut-Off railroad line in northwest New Jersey. Located between approximately mileposts 51.8 and 52.3 in Byram Township, the cut was constructed between 1908 and 1911 by contractor David W. Flickwir. (During construction, Lackawanna Railroad Chief Engineer, Lincoln Bush, would leave the railroad and join Flickwir's construction company to form the Flickwir & Bush construction company.) The cut, which was created by removing fill material obtained by blasting with dynamite or other methods, is 0.53 miles (0.64 km) long, has an average depth of 45 feet (14 m), and a maximum depth of 110 feet (34 m).