<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Hudson Valley comprises the valley of the Hudson River and its adjacent communities in the U.S. state of New York, from the cities of Albany and Troy southward to Yonkers in Westchester County . Depending upon the definition delineating its boundaries, the Hudson Valley encompasses a growing metropolis which is home to between 3 and 3.5 million residents centered along the north - south axis of the Hudson River . </P> <P> The Hudson River valley runs primarily north to south down the eastern edge of New York State, cutting through a series of rock types including Triassic sandstones and redbeds in the south and much more ancient Precambrian gneiss in the north (and east). In the Hudson Highlands, the river enters a fjord cut during previous ice ages . To the west lie the extensive Appalachian highlands . In the Tappan Zee region, the west side of the river has high cliffs produced by an erosion - resistant diabase; these cliffs range from 400--800 feet in height . </P>

Where does the hudson valley start and end