The primary river separating New Jersey and New York is the Hudson River. Flowing south through eastern New York, it acts as a grand watery boundary between the island of Manhattan and the New Jersey cities of Jersey City, Hoboken, and Weehawken. This iconic waterway is crossed by the George Washington Bridge and several tunnels, including the Lincoln and Holland Tunnels. Further south, the boundary is also defined by the Kill Van Kull and the Arthur Kill, which separate Staten Island from the New Jersey mainland. To the north, the river is flanked by the dramatic cliffs of the Palisades. In 2026, the Hudson remains one of the busiest and most recognizable commercial and recreational waterways in the United States, providing a stunning backdrop for the skylines of both states. It serves not only as a physical border but as a vital transportation artery for the millions of commuters and travelers moving throughout the New York metropolitan area every single day.