Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock ( ) or https://
means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
This geodatabase includes 4 polygon-based feature classes representing different scales and levels of detail: 1) Full spatial detail, over 16,000 polygons mapped to Group and Alliance level....
data.gov
An official website of the GSA's Technology Transformation Services