section_path: Geography
section_name: Geography
paragraph_text: Geography
  
  New York City is situated in the northeastern United States, in southeastern New York State, approximately halfway between Washington, D.C. and Boston. Its location at the mouth of the Hudson River, which feeds into a naturally sheltered harbor and then into the Atlantic Ocean, has helped the city grow in significance as a trading port. Most of the city is built on the three islands of Long Island, Manhattan, and Staten Island.
  
  During the Wisconsin glaciation, 75,000 to 11,000 years ago, the New York City area was situated at the edge of a large ice sheet. The erosive forward movement of the ice (and its subsequent retreat) contributed to the separation of what is now Long Island and Staten Island. That action left bedrock at a relatively shallow depth, providing a solid foundation for most of Manhattan's skyscrapers.
  
  The Hudson River flows through the Hudson Valley into New York Bay. Between New York City and Troy, New York, the river is an estuary. The Hudson River separates the city from New Jersey. The East River—a tidal strait —flows from Long Island Sound and separates the Bronx and Manhattan from Long Island. The Harlem River, another tidal strait between the East and Hudson rivers, separates most of Manhattan from the Bronx. The Bronx River, which flows through the Bronx and Westchester County, is the only entirely freshwater river in the city.
  
  The city's land has been altered substantially by human intervention, with considerable land reclamation along the waterfronts since Dutch colonial times; reclamation is most prominent in Lower Manhattan, with developments such as Battery Park City in the 1970s and 1980s. Some of the natural relief in topography has been evened out, especially in Manhattan.
  
  The city's total area is 468.484 square miles (1,213.37 km). 302.643 sq mi (783.84 km) of the city is land and 165.841 sq mi (429.53 km) of it is water. The highest point in the city is Todt Hill on Staten Island, which, at 409.8 feet (124.9 m) above sea level, is the highest point on the eastern seaboard south of Maine. The summit of the ridge is mostly covered in woodlands as part of the Staten Island Greenbelt.