These large-scale maps show the boundaries and numbers for all census blocks within a county. In addition to state and county, these maps show the boundaries, names, and codes for American Indian areas, Alaska Native areas, Hawaiian home lands, county subdivisions, places, and census tracts. These maps also show and label state legislative districts and voting districts (the geographic entities that the states submitted during their participation in the early phases of the Census Redistricting Data Program). The P.L. 94-171 county block maps also show and label base features, such as roads, railroads, and hydrography. The intent of this series is to show each county on the fewest number of map sheets possible and at the maximum practical scale, depending on the size and shape of the county and the density of the tabulation census blocks. Census block density affects the display of census block numbers and feature identifiers. Each county is covered by one or more parent map sheets at a single scale. Inset map sheets at larger scales were created as required to show the map content described above. An index map showing the sheet configuration is included for all counties requiring more than one parent map sheet. The map sheet size is 36 by 32 inches.

Each set of county block maps is accompanied by a Census Block to Map Sheet relationship file. These semi-colon delimited text files include a record for each census block within the county, consisting of the corresponding state, county, tract, and block codes for the block and a list of all map sheet numbers that the block appears on.