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.