<P> The Hudson River separates the Bronx on the west from Alpine , Tenafly and Englewood Cliffs in Bergen County , New Jersey ; the Harlem River separates it from the island of Manhattan to the southwest ; the East River separates it from Queens to the southeast ; and to the east , Long Island Sound separates it from Nassau County in western Long Island . Directly north of the Bronx are ( from west to east ) the adjoining Westchester County communities of Yonkers , Mount Vernon , Pelham Manor and New Rochelle . ( There is also a short southern land boundary with Marble Hill in the Borough of Manhattan , over the filled - in former course of the Spuyten Duyvil Creek . Marble Hill 's postal ZIP code , telephonic area codes and fire service , however , are shared with the Bronx and not Manhattan . ) </P>
which river separates the bronx in new york city from manhattan island
Harlem River