The Hudson River is the primary body of water that separates New Jersey from the island of Manhattan. It serves as a natural and political boundary between the two states, stretching approximately 315 miles from its source in the Adirondack Mountains down to the Atlantic Ocean. For commuters and travelers, the river is crossed via several iconic engineering marvels, including the George Washington Bridge to the north, and the Lincoln and Holland Tunnels further south. Additionally, the NY Waterway ferry system and the PATH train provide vital transit links beneath and across the water. Historically, the Hudson was a major artery for trade and exploration, famously navigated by Henry Hudson in 1609. Today, the riverfront on both sides—Manhattan's West Side and the New Jersey "Gold Coast" cities like Hoboken and Jersey City—has been revitalized with extensive parks and promenades, offering some of the most famous skyline views in the world. The river is tidal as far north as Troy, New York, meaning it functions more like a long, narrow estuary in the section adjacent to Manhattan.