The Tappan Zee Bridge is a bridge in lower New York. It is three miles long. It goes across the Hudson River. It connects Westchester and Rockland Counties. The bridge opened in 1955. It took traffic from other bridges and ferries in the area. The bridge is about 25 miles north of New York City. The city can be seen from the bridge on a clear day. The bridge carries seven lanes of the New York State Thruway.