Rockland County located in New York is the southernmost county on the west side of the Hudson River in the U.S. state of New York  and part of the  New York-Newark-Jersey City, NY-NJ-PA Metropolitan Statistical Area. The county's population, as of the 2010 census, was 311,687, increasing by 3.9% to a 2014 Census estimate of 323,866. The county seat is New City. It is the third most densely populated county outside of New York City within New York State (after Nassau and neighboring Westchester counties, respectively). Although Rockland County does not directly border any New York City boroughs, it lies only 9 miles northwest of the city at their closest points, and is accessible through 10 exits on the New York State Thruway. The name derives from "rocky land", as the area was described by early Dutch and English settlers.