Hudson River

rivers · New York · geography · geology

Born in mountains. The Hudson River starts at Henderson Lake high up in the Adirondack Mountains. From there, it travels 315 miles southward toward the ocean.

Tidal all the way up. The lower half of the river is a tidal estuary, meaning seawater flows in and out with the tides. Even at the city of Troy, far north, the water level rises and falls with the ocean's pull.

Carved by ice age glaciers. Long ago, massive glaciers shaped the Hudson River valley into a deep fjord, which is why the river is deeper than the ocean water it flows into. This ancient glacial carving made the Hudson unique among major rivers.

Border between states. The Hudson River marks the line between New York and New Jersey. It also divides many county borders within upstate New York, making it an important geographical boundary.

Gateway to the ocean. The Hudson flows into New York Bay, a tidal estuary nestled between New York City and Jersey City, which then drains into the Atlantic Ocean.