Online Sources for Geography Shapefiles

While NAVETEQ datasets are available they are limited and it may be necessary to find map layers that better suit your business needs.  In the world of Geographic Information Systems (GIS) maps are shared via shapefiles. 

While not a definitive list the following sites are the most stable at the time of this post.

My first source for United States related mapping data is the United State Census Bureau:

            http://www.census.gov/geo/maps-data/data/tiger.html

For most mapping needs the Cartographic Boundary Shapefiles is sufficient.

Other sites include:

Natural Earth

            http://www.naturalearthdata.com/

GeoCommons

            http://geocommons.com/

DIVA-GIS

            http://www.diva-gis.org/

National Atlas

            http://www.nationalatlas.gov/atlasftp.html

GISDataDepot

            http://data.geocomm.com/

MapCruzin

            http://www.mapcruzin.com/download-free-arcgis-shapefiles.htm

ESRI

            http://www.arcgis.com/home/gallery.html

 
Global Administrative Areas (added 3/30/2015)

            http://gadm.org/

When shapefiles are downloaded they are usually in an archive (zip) and there are at a minimum 4 files within the archive.

• The .dbf file contains the attribute metadata for the geometry data.  Some sources of shapefiles have fewer or more columns of metadata.  Once the shapefile is loaded into the database a table alter can be done to add more columns for additional attributes to allow for linking columns to the BI data. 
• The .prj file contains spatial projection information for the geometry.
• The .shp and .shx files contain the binary data for the geometry.