It is important to know that there are 3 "Riverheads" (from smallest to largest, in order of acreage):
1. There is the Hamlet of Riverhead;
2. There is the "Riverhead, NY 11901" ZIP Code postal zone, and it includes the Hamlet of Riverhead and parts of other adjacent hamlets within its service area; and,
3. There is the Town of Riverhead, and it includes 7 hamlets as well as the "Riverhead, NY 11901" ZIP Code postal zone and other postal zones, within its borders.
For those who may not be familiar with Riverhead:
Riverhead is a hamlet (an unincorporated area) in the central part of the Town of Riverhead, in the northeast part of Suffolk County, along the Riverhead/Southampton town line.
Beginning on the north and moving in a clockwise direction, the Hamlet of Riverhead in the Town of Riverhead is bordered on the north by Long Island Sound; on the east by the Hamlet of Northville and the Hamlet of Aquebogue; on the south by the Hamlet of Riverside in the Town of Southampton (the Riverhead/Southampton Town line); and, on the west by the Hamlet of Calverton and the Hamlet of Baiting Hollow.
The Hamlet of Riverhead has a different border than does the "Riverhead, NY 11901" ZIP Code postal zone (i.e., a place can have a "Riverhead, NY 11901" mailing address and not be in the Hamlet of Riverhead): places that have a "Riverhead, NY 11901" mailing address that are not in the Hamlet of Riverhead are in the Hamlet of Northampton, the Hamlet of Riverside and the Hamlet of Flanders in the Town of Southampton, as well as in the Hamlet of Baiting Hollow, the Hamlet of Northville and the Hamlet of Aquebogue in the Town of Riverhead.
For a good set of town-by-town maps showing all the villages and hamlets in each of LI's 13 towns (3 in Nassau County and 10 in Suffolk County):
http://www.city-data.com/forum/long-...-resource.html