The New Haven Railroad operated local service on the Shore Line up until its merger with Penn Central on January 1, 1969, when most commuter service east of New Haven was abandoned. Intercity service continued, but generally only stopped at New Haven, Old Saybrook, and New London. Penn Central continued to operate the "Clamdigger", a single daily New London-New Haven round trip with local stops, as well as a New London-Boston round trip. Amtrak took over the "Clamdigger" along with most intercity passenger service, in May 1971. In January 1972, Amtrak discontinued the "Clamdigger" and Penn Central cut the New London-Boston trip.