The Hudson is an amazing resource: a tidal river that links the communities of the valley economically, culturally, and ecologically. Home to more than 200 species of fish, the Hudson serves as a nursery ground for such important fish as sturgeon, striped bass and American shad and has been a cradle of human development for thousands of years. The river is profoundly influenced by the ocean's tides for over half its length, creating an estuary which stretches 153 miles and includes a wide range of wetland habitats. The reserve sites reflect this diversity, from the brackish marshes of Piermont to the slightly brackish wetlands of Iona Island, and the freshwater tidal mudflats and marshes of Tivoli Bays and Stockport Flats.