README FILE 
 
Census Tract Reference Maps from the 23rd Census of Population and Housing, 2010 
 
Record Group 29: Records of the Bureau of the Census 
 
TR-0029-2018-0012 
 
This series consists of county-based maps that show and label the census tracts as delineated to 
support 2010 Census data dissemination.  
 
There are 4,924* map files for census tract groups within 3,312 counties. Each county is covered 
by one or more parent map sheets at a single scale. The agency created inset map sheets at larger 
scales where there are clusters of census tracts that cannot be identified at the parent map scale. 
There is an index map showing the sheet configuration for all counties requiring more than one 
parent map sheet. Each set of census tract reference maps is accompanied by a “Census Tract to 
Map Sheet” (CT2MS) relationship file that includes a record for each census tract within the 
county, consisting of the code and name of the tract, and a list of all map sheet numbers on 
which the tract appears. 
 
Example:  
DC10CT_C06083_000.pdf 
 
= Index Sheet 
DC10CT_C06083_001.pdf 
 
= Parent Sheet 1 
… 
DC10CT_C06083_0011.pdf  
= Parent Sheet 11 
DC10CT_C06083_CT2MS.txt   
= Census Tract-to-Map Sheet 
 
In January 2020, to facilitate access to these records, the files that support a particular census 
tract group were “zipped” into 3,312 separate ZIP files. Found within each ZIP file are: 
 
 This NARA-created README file (Readme_DC10CT.pdf) 
 The “Census Tract-to-Map Sheet” (CT2MS) relationship file in ASCII text (.txt)  
 The map files in Portable Document Format (.pdf) for the respective census tract.  
 
*NARA received duplicate versions of files for some counties. The duplicate versions are not 
available online. 
 
Electronic Records Reference Branch (RDER) 
Prepared: February 4, 2020