Westchester County is located in the United States in the southern part of the state of New York. Westchester covers an area of 450 square miles (1,200 km2) and has a population of 949,113 according to the 2010 Census, residing in 45 municipalities. It was named after the city of Chester in England.
The majority of the principal roadways and all the railroad lines in Westchester run north to south, following the orientation of the river valleys. Residential development has historically followed this pattern, spreading north as densities increased in the South and Central County areas. Overall journey-to-work patterns are also primarily north to south because of the concentration of employment centers in New York City and southern and central Westchester.
The areas of Westchester (and lower Putnam County) are as follows: