II.

Description

The Hudson has a winding upper course and flows almost directly south below Hudson Falls. The headwaters of the river are the outlets of several small lakes in the Adirondacks; the largest headstream is the Opalescent River, which flows out of Lake Tear of the Clouds. The river falls rapidly in the upper waters, having a drop of about 15 m (about 50 ft) at Glens Falls, the first sizable city on its course. At Cohoes the Hudson is joined by its principal tributary, the Mohawk. From Troy to the mouth of the Hudson the effects of tides are observable. The depression of the Hudson valley floor and the effects of tidewater make the river navigable by small oceangoing vessels to Albany and Troy, about 240 km (about 150 mi) from its mouth. As a tidal estuary, the Hudson has a large volume of water, far out of proportion to the area it drains, which is about 34,630 sq km (about 13,370 sq mi).

Below Albany the channel of the river is in places very narrow, and the banks are lined with some high, steep hills and mountains. Flowing past the Catskill Mountains and the Hudson Highlands, below Newburgh, the river is famous for beautiful scenery. Emerging from the highlands, the river widens into a lakelike expanse called Tappan Zee. Farther south, near its mouth, the river forms the boundary between New York and New Jersey for about 29 km (about 18 mi). In this region the western shore is formed by a great cliff of traprock known as the Palisades.

The Hudson River is one of the most important commercial waterways in the eastern U.S., forming part of a trade route to the interior of North America. The river is joined just north of Albany by divisions of the New York State Canal System, which link the Hudson to Lake Champlain, the Great Lakes, and the St. Lawrence River. The commercial importance of the Hudson declined somewhat after the opening, in 1959, of the St. Lawrence Seaway, which provides an alternate route from the Atlantic to the interior. A major problem of the 20th century has been the severe pollution of the Hudson by industrial wastes and sewage.