From the Adirondack Mountains to New York City, the Hudson flows through 315 miles of eastern New York. The lower half of the Hudson is an estuary influenced by ocean tides and saltwater.

Bordered by 15 New York State counties, the estuary is defined by the Federal Dam at Troy and the Verrazano Narrows in New York City. The Estuary has a 4 foot tidal range that extends to Troy. On average, (depending on the amounts of seasonal precipitation and freshwater runoff) the salt front is held between the Tappan Zee and Yonkers, moving toward Newburgh Bay during the summer.

The Hudson River is one of the most extensive freshwater tidal ecosystems in the northeastern U.S. The estuary marshes and tidal flats contribute essential nutrients to aquatic and terrestrial food webs. The River’s main stem, marshes and freshwater tributaries provide vital habitat for invertebrates, fish, reptiles and amphibians, birds and mammals. The Hudson Valley is also a great place for people. Rich in cultural history, biological and geological diversity, The River and bordering communities provide numerous opportunities for recreation, including boating, fishing, swimming and hiking opportunities.

Like many of our coastal water bodies, the Hudson Estuary is stressed and continues to face many challenges. In 1987 the New York State Legislature passed the Hudson River Estuary Management Act, a law creating a plan and programs to conserve the tidal Hudson River and its associated shorelands. Over two decades of hard work by citizen groups, government agencies, non-government organizations and individuals has helped conserve one of New York’s great coastal resources. New York Sea Grant Extension has had a Hudson Estuary specialist working in this region since the early1990’s.