Hudson, river, c.315 mi (510 km) long, rising in Lake Tear of the Clouds, on Mt. Marcy in the Adirondack Mts., NE N.Y., and flowing generally S to Upper New York Bay at New York City; the Mohawk River is its chief tributary. The Hudson is navigable by ocean vessels to Albany and by smaller vessels to Troy; leisure boats and self-propelled barges use the canalized section between Troy and Fort Edward, the head of navigation. Divisions of the New York State Canal System connect the Hudson with the Great Lakes and with Lake Champlain and the St. Lawrence River.
The Hudson is tidal to Troy (c.150 mi/240 km upstream); this section is considered to be an estuary. The upper course of the river has many waterfalls and rapids. The middle course, between Albany and Newburgh, is noted for the Catskill and Shawangunk mts. on the west and by the large estates (the Roosevelt home at Hyde Park is the most famous) on the east bank. From Newburgh to Peekskill the river crosses the mountainous and forested Hudson Highlands in a deep, scenic gorge. The United States Military Academy at West Point overlooks the river there, and Bear Mt. Bridge spans this section. Near Tarrytown the river widens to form Tappan Zee, which is crossed by the Tappan Zee Bridge; from there to its mouth the Hudson is flanked on the west by the sheer cliffs of the Palisades. At the mouth are the ports of New York and New Jersey. The Hudson forms part of the New York–New Jersey border, and the two states are linked by the George Washington Bridge, the Holland and Lincoln vehicular tunnels, and railway tubes.
First sighted by Verrazano in 1524, the river was explored by Henry Hudson in 1609. It was a major route for Native Americans and later for the Dutch and English traders and settlers. During the American Revolution both sides fought for control of the Hudson; many battles were fought along its banks. In 1825 the Erie Canal (now part of the state canal system) linked the river with the Great Lakes, providing the first all-water trans-Appalachian route. Many industries are located on the Hudson's banks, and pollution by raw sewage and industrial wastes became a serious problem in the 1900s; antipollution legislation passed in 1965 has sought to protect the river from further contamination. Although pollution continued throughout the 1970s and 80s, the state and municipal governments in addition to environmental groups have contributed a significant clean-up effort, complete with antipollution regulation. The Hudson is featured in the legend of Rip Van Winkle and other stories of Washington Irving.
See R. Van Zandt, comp., Chronicles of the Hudson (1971); A. R. Talbot, Power along the Hudson (1972); A. G. Adams, The Hudson Through the Years (1983).