The Hudson River Valley is a bioregional land node organized around Muhheakantuck, the great tidal estuary the Mohican people named the river that flows both ways, where the Atlantic Ocean pushes saltwater more than 150 miles inland to meet the freshwater descending from the Adirondack high peaks. The river runs 315 miles from Lake Tear of the Clouds on the flank of Mount Marcy to New York Harbor, with its lower 153 miles functioning as a drowned glacial fjord whose tides rise and fall twice daily as far north as the Federal Dam at Troy. The valley is conventionally read in three reaches: the Upper Hudson of Greene, Columbia, Albany, and Rensselaer counties, where the navigable river meets the Erie and Champlain Canals; the Middle Hudson of Ulster, Dutchess, Orange, and Putnam counties, where the river narrows through the majestic Hudson Highlands beneath the Catskill and Shawangunk ranges; and the Lower Hudson of Westchester and Rockland counties, where marshes and hills give way to the cityscape of Manhattan. As a single land node, the Hudson River Valley is composed of many nested places, communities, and stewardship projects, from Indigenous-led land-return efforts to riverkeeper patrols, tidal-marsh research reserves, regenerative farms, and the heritage sites that line both banks. The estuary supports more than two hundred species of fish and holds the only significant acreage of tidal freshwater wetlands in New York State, anchoring one of the highest concentrations of biodiversity in the Northeast, as documented by the Hudson River Estuary Program. This is a working, living, and storied landscape, the same valley the geologian Thomas Berry described in his bioregional story of the Hudson as a single organic community of river, lowland, hills, sunlight, rain, and all the creatures who belong to it.