Gazetteer References & Data Sources

Database & Map Update Cycles

  1. Geographic data for physical, cultural and historic features is updated 6 times per year. Last update: August 1, 2017.
  2. The ZIP Code database and maps are each updated 4 times per year but with different update cycles. The ZIP Code database was last updated on August 1, 2017 and the ZIP Code maps were last updated on August 30, 2017.
  3. The School Attendance Zone Maps are updated 4 times per year. Last update: May 9, 2017.
  4. The Census Demographic Data is updated annually. Last update: July 1, 2017.

Geographic Data

The geographic data for the physical, cultural and historic features is based on the Geographic Names Information System (GNIS). The GNIS is maintained by the US Geological Survey (USGS) and is the official Federal database for domestic geographic feature names and locative information.

Census Demographic Data

The annual census demographic estimates and 5-year forecasts are based upon data produced by Esri Demographics. Their estimates and forecasts use the latest US Census Bureau annual American Community Survey (ACS) as a starting point. They then combine additional data from multiple sources including residential postal delivery counts from the USPS, a time series of county-to-county migration patterns from the IRS, building permits, housing starts and local data sources that tested well against the most recent census. For more detailed information: Methodology Statement: 2017/2022 Esri US Demographic Updates.

School Profiles

The primairy data source for our school profile data is the National Center for Education Statistics (NCES) at the US Department of Education.


  1. The base interactive maps and aerial photos are produced by the Google Maps API.
  2. Boundary Maps for incorporated places, Census Designated Places, counties and county subdivisions are based on data provided by Esri.
  3. The School Attendance Zone Maps and ZIP Code Maps are based on data provided by Pitney Bowes.
  4. The Congressional District Maps are based on data provided by the U.S. Census Bureau

Photos, Directory & Jobs

  1. The Local Area Photos are provided by Trover.
  2. The Local Directories of Business Government and Social Services are powered by Google.
  3. The Local Job Listings are provided by CareerBuilder.
Puerto Rico’s Forgotten Island Vieques Needs Help

Puerto Rico’s Forgotten Island Vieques Needs Help

In the very early morning hours of September 20, 2017, the eyewall of Hurricane Maria passed over the tiny island of Vieques, Puerto Rico as a Category 5 hurricane, before moving westwards to mainland Puerto Rico. Maria ravaged the 60-square mile island with sustained winds of over 150 MPH and storm surges of over 12 feet, destroying homes, local businesses and causing widespread devastation.

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