Gazetteer References & Data Sources
Database & Map Update Cycles
- Geographic data for physical, cultural and historic features is updated 6 times per year. Last update: December 1, 2018.
- 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 November 1, 2018 and the ZIP Code maps were last updated on November 1, 2018.
- The School Attendance Zone Maps are updated 4 times per year. Last update: September 13, 2018.
- The Census Demographic Data is updated annually. Last update: July 1, 2018.
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: 2018/2023 Esri US Demographic Updates.
The primary data source for our school profile data is the National Center for Education Statistics (NCES) at the US Department of Education.
- The base interactive maps are based on data produced by the OpenStreetMap.org (OSM) project. The project is a collaborative effort of over 2 million registered users who collect and update geographic information on an ongoing basis. The data we use to produce our maps is updated every 60 days.
- Boundary Map data for incorporated places, Census Designated Places, counties and county subdivisions are based on data provided by Esri and is overlayed on our base maps.
- The School Attendance Zone Maps and ZIP Code Maps are based on data provided by Pitney Bowes.
- The Congressional District Maps are based on data provided by the U.S. Census Bureau
Photos, Places, Geocoding, & Jobs
- The Local Area Photos are provided by Trover.
- The listings used to create the local Top 20 Popular Places and related data are powered by HERE. They pioneered in-car navigation systems over 30 years ago - first as NAVTEQ, later as Nokia Maps, and now as HERE. The company draws on more than 80,000 data sources and they relie on local source data for information about local business and attractions.
- Forward Geocoding, taking an address and translating it into geographic coordinates, is performed by HERE.
- The Local Job Listings are provided by CareerBuilder.