A Gazetteer for the United States and Canada

Ayer, Massachusetts

Nearby Census Genealogy
Cemeteries Tidbits &
Other MA

Various Identification Codes ...

GNIS Codes ...

The U.S. Board on Geographic Names (BGN) was created to address the problems caused by spelling and naming variations. The BGN will usually recognize an existing name or, when necessary, establish a new name for a geographic feature (such as a mountain, lake, river, stream, city, town, village, dam, bridge, etc).

The BGN names are kept in a database called the Geographic Names Information System (GNIS) and it is the official Federal repository. The GNIS is operated and maintained by the U.S. Geological Survey (USGS).

A unique and permanent identification number has been assigned for each name in the GNIS database. These names and identifiers are definitive and it is intended that they are to be used by all departments of the Federal Government:

GNIS ID for Ayer: 618215

GNIS ID for Middlesex County: 606935

GNIS ID for Massachusetts: 606926

FIPS Codes ...

In a past effort, various federal agencies worked together to create a set of codes with a purpose similar to the GNIS codes. These codes are called the Federal Information Processing Standard (or the FIPS 55 codes). Although they are still used by some organizations, the FIPS codes are obsolete and will ultimately be replaced by the GNIS codes.

The following FIPS codes apply to Ayer:

Place (Community) Code:  03040
State Code:  25 (Massachusetts)
County Code:  017 (Middlesex County)

Since the Place and County FIPS codes are not unique and can be repeated in other States, it's necessary to combine the State code with the Place and County FIPS codes to uniquely identify them - for example:

State/Place Code:  25/03040
State/County Code:  25/017

As already mentioned, the FIPS codes are to be replaced by the GNIS codes. The following reflect those changes:

 FIPS Code   translates to   GNIS Code
State of Massachusetts:    25   606926
Middlesex County:    25/017   606935
Ayer:    25/03040   618215

GPS Location - GNIS vs Census ...

An important aspect of the GNIS code is that it assigns a GPS location (the latitude/longitude) to the geographic feature. This location is simply a point on the map and does not represent the size or shape of the feature. In the case of Ayer, it is a point within Ayer that might be a post office, the city hall or simply an intersection - the point should really be considered arbitrary and only indicating a general location.

For Ayer, the GNIS GPS location is given as:

Lat:   42° 33' 40"   (or 42.56°)

Lon:   -71° 35' 23"   (or -71.59°)   [Map]

Determined by its statistical needs, the Census Bureau has defined a sampling area for Ayer - this area also contains a map point. As with the GNIS code, the location of the Census point should be considered as being arbitrary within the sampling area.

For Ayer, the Census 2010 GPS location is given as:

Lat:   42° 33' 41"   (or 42.56°)

Lon:   -71° 34' 27"   (or -71.57°)   [Map]

The map point defined by the Census Bureau lies 4,191 feet to the east<1> of the point given by the GNIS (see above).

You might note that the GPS location given for the 2010 Census is different than the location that was specified by the 2000 Census:

Lat:   42° 33' 32"   (or 42.56°)

Lon:   -71° 34' 33"   (or -71.58°)   [Map]

The GPS location given for the 2000 Census lies 1,034 feet to the southwest<2> of the point given by the 2010 Census.

Regional Codes ...

For statistical purposes, the US Census Bureau has divided the country into four Regions. Ayer is located in Region #1 (the Northeast Region).

In turn, the US Census Bureau has further divided each Region into Divisions. Ayer is located in Division #1 (the New England Division).

The Office of Management and Budget (OMB) has created ten Federal Regions. Ayer is located in Region I (Region 1).

The Federal Emergency Management Agency (FEMA) has created ten Management Regions. Ayer is located in Region I (Region 1).

ZIP Codes ...

While some people have used a ZIP code to identify a community, the purpose of the ZIP code was to make mail delivery more efficient by grouping addresses together. Although the ZIP Code doesn't specifically identify a community like Ayer, it does identify addresses that are in (or near) Ayer. It's important to remember that the boundaries of a ZIP Code are defined by the needs of the USPS and can be changed, re-assigned or overlapped with other ZIP Codes.

The ZIP code for Ayer: 01432<3>

Referenced GNIS Records ...

GNIS ID #611084   (Name of Record: Ayer)

Class: populated place

A place or area having clustered or scattered buildings and a permanent population (such as a city, settlement, town or village). The boundaries may or may not coincide with the perceived population.

A 'populated place' record may have a corresponding 'census' or 'civil' record. The information contained in the 'populated place' record applies only to the class and should not be confused with either the 'census' and 'civil' classes.

County: Middlesex

Map Name: Ayer

Lat: 42.5612021       Lon: -71.5897897   [Map]

Elev: 73 ft.

GNIS ID #618215   (Name of Record: Town of Ayer)

Class: civil

A political division formed for administrative purposes (such as a borough, county, incorporated place, parish, town or township).

A 'civil' record may have a corresponding 'census' or 'populated place' record. The information contained in the 'civil' record applies only to the class and should not be confused with either the 'census' and 'populated place' classes.

County: Middlesex

Map Name: Ayer

Lat: 42.5667577       Lon: -71.566178   [Map]

Elev: 85 ft.

Referenced FIPS Records ...

FIPS Code: 25/03005   (Place Name: Ayer (Town of))

County: Middlesex     (FIPS State/County: 25/017)

Class: T1

MSA Code: 1120

FIPS Code: 25/03040   (Place Name: Ayer)

County: Middlesex     (FIPS State/County: 25/017)

Class: U1

GSA Code: 60

MRF Code: 240

MSA Code: 1120

Other Roadside Stops ...

Visit our Community Index for Massachusetts

About Middlesex County

About Massachusetts

Off-the-Road Links ...

The official website for Ayer:

The official website for State of Massachusetts:

The official website of the U.S. Board on Geographic Names (BGN)

The official website of the U.S. Geological Survey (USGS)

The official website of the U.S. Census Bureau

The official website of the U.S. Office of Management and Budget (OMB)

The official website of the U.S. Federal Emergency Management Agency (FEMA)

Footnotes ...

<1>The calculated bearing (or angle) to the GNIS-supplied location is 271 degrees and a distance of 4,191 feet.
<2>The calculated bearing (or angle) to the 2000 Census location is 150 degrees and a distance of 1,034 feet.
<3>When looking for a ZIP Code, whether Ayer or elsewhere, it's always best to check the website of the United States Postal Service (USPS).




Sitemap Privacy
of Use



Copyright 2020
All Rights Reserved

Please keep in mind that we can not guarantee the accuracy or timeliness of the information on this website, so use with care. We encourage you to double-check the information that is critical to you.

If you've found an error or have additional information that you would like to share, please don't hesitate to write. Click here to contact us.

This page was last modified: 18 Apr 2022