These county (or county equivalent)-based reference maps show and label the census tracts as delineated to support 2020 Census data dissemination. These maps also show and label federal and state American Indian reservations, Alaska Native Regional Corporations, states (or state equivalents), counties, county subdivisions, consolidated cities, and places. Additionally, these maps display a base feature network including roads, railroads, and water bodies. These features are labeled as scale permits. The map sheet configuration is optimized to keep the number of map sheets to a minimum. Each county will be covered by one or more parent map sheets at a single scale. Inset map sheets at larger scales are created where there are clusters of census tracts that cannot be identified at the parent map scale. An index map showing the sheet configuration is created for all counties requiring more than one parent map sheet. The map sheet size is 36 by 42 inches. 

Each county's map is accompanied by a Census Tract to Map Sheet (CT2MS) relationship file. This semicolon-delimited text file includes one record for each census tract within the county and a list of all the map sheets where that census tract appears. In addition to the 11-character census tract full code, each record contains the codes for the corresponding state, county, and census tract.

A catalog file including the file name, entity name, and total number of map sheets is provided in the directory for each state. The map file (PDF) and associated text files are in county-based directories.

Map Viewing Tips: These maps were designed to be viewed with Adobe Reader (version 6 or later), which is available free from Adobe. These maps are large and use complex symbology, such as wave pattern fill for water bodies. If a browser opens them in another PDF reader, the screen display may not accurately reproduce the map. For best viewing in Adobe Reader, uncheck the “Enhance thin lines” option, found under the Edit tab: Preferences > Category: Page Display > Rendering section.