Geography of The Bronx, New York

Bronx County has a total area of 57 square miles, of which 42 square miles (73%) are land and 15 square miles (27%) are water, according to the United States Census Bureau.

The Bronx is the northernmost borough of New York City, the southernmost county on the mainland of New York State, and the only portion of New York City that is almost fully on the North American continent. Its bedrock consists mostly of Fordham gneiss, a high-quality metamorphic rock with abundant pink feldspar. Politically a part of Manhattan but now geographically a part of the Bronx, Marble Hill derives its name from the creation of Inwood marble there, as well as in Inwood, Manhattan, and portions of the Bronx and Westchester County.

The Hudson River divides the Bronx on the west from Alpine, Tenafly, and Englewood Cliffs in Bergen County, New Jersey; the Harlem River divides it from the island of Manhattan to the south; the East River divides it from Queens to the southeast; and Long Island Sound divides it from Nassau County in western Long Island to the east. Directly north of the Bronx are the bordering Westchester County communities of Yonkers, Mount Vernon, Pelham Manor, and New Rochelle, although they are physically separated by water. Marble Hill shares its postal ZIP code, telephone area codes, and fire service with the Bronx and not with Manhattan.

The Bronx River originates in Westchester County, travels through the borough, and empties into the East River; it is the only river in New York City that contains only freshwater. The Hutchinson River, a tiny river, flows through the East Bronx and empties into Eastchester Bay.

The Bronx's highest elevation at 280 feet is in the northwest corner.

Bronx Population

The Bronx is projected to have around 1.5 million residents in 2021, making it the third most populated county in New York City. The borough is one of the most populous areas in the United States and is known for its demographic diversity. There are an increasing number of young professionals, families, and international immigrants.

There were 463,212 households, out of which 38.1% had children under the age of 18 living with them, 31.4% were married couples living together, 30.4% had a female householder with no husband present, and 32.0% were non-families. 27.4% of all households were made up of individuals, and 9.4% had someone living alone who was 65 years of age or older. The average household size was 2.78 and the average family size was 3.37.