ERS GIS Map Services and API User Guide

All of the ERS mapping applications, such as the Atlas of Rural and Small-Town America, the Food Environment Atlas, and the Food Access Research Atlas, use map services developed and hosted by ERS as the source for their map content. These map services are open and freely available for use outside of the ERS map applications. Developers can include ERS maps in applications through the use of the map service REST API, and desktop GIS users can use the maps by connecting to the map server directly.

General Map Service Documentation

Over 23 ERS map services have been created, each containing anywhere from 4 to 70 map layers. The majority of the services consist of national maps displaying data at the county-level. (The Food Access Research Atlas service is Census-tract based.) A good way to discover and browse the available services and maps is to use the ERS map applications themselves; all use a similar data organization scheme of "Categories" and "Maps." Each category in the application corresponds to a map service; each map is a layer in that map service.(The Food Access Research Atlas is the exception to this scheme as it uses only a single ERS map service, plus an ESRI-hosted background map.)

The ARC GIS REST Services Directory lists all available map services. Note that updates to the Supplemental Nutrition Assistance Program (SNAP) Data System have been discontinued.

Note: All mapservices are accessible only via https.

Summary of ERS map services and where they are used
Map service Description, type of content Where used
background Generic landmass/water body used for map backgrounds All ERS map atlases except the Food Access Research Atlas

Access and proximity to grocery stores;
Food and nutrition assistance;
Health and physical activity;
Food insecurity;
Local foods;
Food prices and taxes;
Restaurant availability and expenditures;
Socioeconomic characteristics;
Grocery store availability.

Most current release date: 9/10/2020

The Food Environment Atlas


Food access measures used in the Food Access Research Atlas: 'foodaccess2019' is the most current version, released 4/27/2021. Prior versions include 'foodaccess2015', released 1/17/2017, and  'foodaccess2010', released 2/2013. The Food Access Research Atlas


County classifications;

Most current release date: 6/8/2021

Atlas of Rural and Small Town America
snap_benefits snap_participation_poverty snap_participation

SNAP benefits;
SNAP participation per person in poverty;
SNAP participation.

Most current release date: 5/28/2013

Supplemental Nutrition Assistance Program (SNAP) Data System (discontinued) 

State and county boundaries and labels
Web Mercator version

Most current release date: 2/2/2018

All ERS map atlases

NASS 2012 Ag Census Map Services

In partnership with NASS, ERS developed the 2012 Ag Census Maps application, and is also hosting the map services for that application. See the NASS map service documentation.

Desktop User Instructions

To use the ERS map services in a desktop application, such as ArcMap or ArcGIS Online:

  • Browse the service description and REST directory to determine which services and maps meet your needs, and
  • Follow the instructions here to add the maps to your document. Use ‘’ as the server specification.

Developer API Instructions

The services can be accessed through ArcGIS Server REST API. JSON and SOAP interfaces are also available. See the detailed documentation, including general usage instructions, service properties, and methods.