Carrier Route Boundary Data - Helena, Montana
=============================================

SAMPLE EXTRACT - August 2026 release (RELVER 202608)

The archive to read if you only read one. Helena carries all three
of the main route types in one place - thirty city, thirteen rural and eight
highway contract. Highway contract routes are the ones the Postal Service
contracts out rather than runs itself, and there are only 10,850 of them among
the 253,594 routes nationally, so they are easy to miss in a smaller extract.

It also demonstrates the limit of this product. Eight Helena ZIP Codes were
queried; five of them are in this file. The other three - 59604, 59620 and
59624 - are PO Box ZIP Codes. They have no delivery area and no carrier, so a
carrier route file has nothing to say about them and they are simply absent.
That is not a gap in the extract; it is what the product is. If you need those
ZIP Codes represented, they exist as point records in the ZIP Code Boundary
Data product.

THIS EXTRACT
------------
    ZIP Codes with routes   5  (59601, 59602, 59623, 59625, 59626)
    ZIP Codes with none     3  (59604, 59620, 59624 - PO Box only)
    Carrier routes          51
    Route types             30 city (C), 13 rural (R), 8 highway contract (H)
    County                  Lewis and Clark County, MT  (COUNTYFIPS 30049)
    Residential deliveries  28,210
    Business deliveries     2,107

WHAT IS IN THE ARCHIVE
----------------------
The same eight formats the licensed national file ships in, all built from the
same query, all at full precision:

    _shapefile.shp / .shx / .dbf / .prj   Esri Shapefile
    _geojson.geojson                      GeoJSON, RFC 7946, longitude first
    _kml.kml                              KML for Google Earth
    _wkt.txt                              pipe-delimited, geometry first
    _csv.csv                              comma-delimited, geom column
    _mssql.sql                            SQL Server / Azure SQL
    _postgre.sql                          PostgreSQL + PostGIS
    _mysql.sql                            MySQL / MariaDB

Everything is WGS84, SRID 4326, decimal degrees. Every record is a polygon -
unlike the ZIP Code boundary file, there are no point records here, so the
shapefile's one-geometry-per-file limit costs you nothing.

"Carrier Route Boundaries Product Documentation.pdf" in this archive is the
full field reference for the product.

ONE THING TO KNOW ABOUT THE GeoJSON
-----------------------------------
Plenty of carrier routes are made of more than one piece - a route jumps a
river, or wraps around a block it does not serve. In the GeoJSON file those
multi-part routes are written as a GeometryCollection of Polygons rather than
as a MultiPolygon.

Most tools read that correctly. GDAL/OGR, GeoPandas, PostGIS and Leaflet all
handle it. Mapbox GL JS and MapLibre GL JS do not - they skip
GeometryCollection features silently, so a route that is in the file simply
never draws, with no error to tell you why. If you are loading this into a GL
map, either convert those features to MultiPolygon first:

    ogr2ogr -f GeoJSON out.geojson in_geojson.geojson -nlt MULTIPOLYGON

or use the shapefile, the WKT or the CSV, all of which carry the same records
as MULTIPOLYGON already. This affects roughly a third of the routes in these
extracts, so it is not a rare edge case - check your count against the number
under THIS EXTRACT above and you will know immediately whether your loader
handled it.

THE FIELDS
----------
    ZIPCRID     ZIP Code and route in one key, e.g. 62056C001. Unique.
    ZIP         the 5-digit ZIP Code the route belongs to
    CR          the route within that ZIP Code, e.g. C001, R003, H008
    NAME        place name
    STATE       2-letter state
    STATEFIPS   2-digit state FIPS
    COUNTYFIPS  5-digit county FIPS (state + county, not county alone)
    LAT / LON   a representative point for the route
    TOTRESCNT   residential deliveries on the route
    SFDU        single-family dwelling units
    MFDU        multi-family dwelling units
    BOXCNT      PO Boxes served - 0 throughout all three of these extracts
    BIZCNT      business deliveries
    RELVER      release version, 202608 for this data

ROUTE TYPES
-----------
The letter that opens CR is the route type:

    C   City          walked or driven from a city post office
    R   Rural         rural delivery, generally longer and lower density
    H   Highway       highway contract - contracted out rather than USPS-run
    B   PO Box        box section
    G   General       general delivery

WHAT THIS SAMPLE IS NOT
-----------------------
It is a small extract, not a trial of the national file. The full product is
253,594 carrier routes across 33,235 ZIP Codes. It is licensed by the area you
need - one or more states, or the national file - so if these three areas look
right, tell us which states you want and we will price it.

The carrier route sits one step below the ZIP Code, and the two products are
built to be used together. If what you actually need is the ZIP Code itself,
that is the ZIP Code Boundary Data product:
https://www.zip-codes.com/zip-code-map-boundary-data.asp

MORE
----
Product page   https://www.zip-codes.com/carrier-route-map-boundary-data.asp
Live demo map  https://www.zip-codes.com/carrier-route-map-boundary-data.asp#demo
Questions      info@zip-codes.com  |  1-800-425-1169

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This sample is provided for evaluation. It may not be redistributed, resold or
published, in whole or in part, without a license.
