Hudson River. The Hudson River is a 315-mile river that flows from north to south primarily through eastern New York in the United States.
The river originates in the Adirondack Mountains of Upstate New York, flows southward through the Hudson Valley to the Upper New York Bay between New York City and Jersey City. It eventually drains into the Atlantic Ocean at New York Harbor.
The river serves as a political boundary between the states of New Jersey and New York at its southern end. Further north, it marks local boundaries between several New York counties.
The lower half of the river is a tidal estuary, deeper than the body of water into which it flows, occupying the Hudson Fjord, an inlet which formed during the most recent period of North American glaciation, estimated at 26,000 to 13,300 years ago. Tidal waters influence the Hudson's flow from as far north as the city of Troy.
The river is named after Henry Hudson, an Englishman sailing for the Dutch East India Company, who explored it in 1609, and after whom Hudson Bay in Canada is also named. It had previously been observed by Italian explorer Giovanni da Verrazzano sailing for King Francis I of France in 1524, as he became the first European known to have entered the Upper New York Bay, but he considered the river to be an estuary. The Dutch called the river the North River-with the Delaware River called the South River-and it formed