Learn about the Hudson River, a major waterway in New York state that flows into the Atlantic Ocean. Discover its origin, course, tributaries, bridges, canals, and environmental challenges.

The Hudson River is the longest river in New York State and flows from the Adirondack Mountains to the Atlantic Ocean. It has a rich ecology, a tidal estuary, and a history of exploration, trade, and war.

The Hudson River is the defining natural feature of a major region of New York State, familiar to millions who drive across its bridges, admire its grandeur from parks and historic sites, or ride the Hudson River Line railroad.

Hudson River. From its start as a crystalline stream rushing through magnificent Adirondack scenery to its entrance into New York Harbor as an estuary alive with striped bass, blue crabs, and even seahorses, the Hudson possesses an abundant and diverse array of natural resources.

Learn about the exploration, colonization, and cultural significance of the Hudson River, a 315-mile (507 km) waterway in New York. Discover the names, tribes, and events that shaped the river's history from pre-Columbian era to present day.

The Hudson River Estuary Program helps people conserve, restore, and enjoy the Hudson River and its valley. The program focuses on the tidal Hudson and adjacent watershed from the federal dam at Troy to the Verrazano Narrows in New York City, including upper New York-New Jersey Harbor (see map of Hudson River Estuary Program Boundary (PDF)).

Learn about the unique features and ecology of the Hudson River, a tidal estuary that combines salt and fresh water. Find out how Riverkeeper protects the river from pollution, invasive species and other threats.