With a population of 8,175,133, New York is the most densely populated major city in the United States. The New York City Metropolitan Area 's population is the United States ' largest, estimated at 18.9 million and is also part of the most populous combined statistical area in the United States, containing 22.2 million people as of 2009 Census estimates.
Most of the southern part of the state is on the Allegheny Plateau, which rises from the southeast to the Catskill Mountains. The western section of the state is drained by the Allegheny River and rivers of the Susquehanna and Delaware systems. The Delaware River Basin Compact, signed in 1961 by New York, New Jersey, Pennsylvania, Delaware, and the federal government, regulates the utilization of water of the Delaware system. The highest elevation in New York is Mount Marcy in the Adirondacks. New York 's borders touch (clockwise from the west) two Great Lakes (Erie and Ontario, which are connected by the Niagara River); the provinces of Ontario and Quebec in Canada; Lake Champlain; three New England states (Vermont, Massachusetts, and Connecticut); the Atlantic Ocean, and two Mid-Atlantic States, New Jersey and Pennsylvania.
New York City is composed of five boroughs. Each borough is coextensive with a respective county of New York State as shown below. Manhattan is the most densely populated borough and is home to Central Park and most of the city 's skyscrapers. The borough is the financial center of the city and contains the