The 2010 Census Block Map Series, also referred to as the Geographic Unit (GU) block maps, is produced to support the 2010 Decennial Census data release. These maps display tabulation geography down to the census block level. The 2010 Census Block Maps are produced for the following entities: counties and statistically equivalent entities, minor civil divisions (MCDs), census county divisions (CCDs) and statistically equivalent entities, incorporated places, census designated places (CDPs), consolidated cities, sub-MCDs, federal American Indian reservations, state American Indian reservations, Oklahoma tribal statistical areas (OTSAs), Alaska Native village statistical areas (ANVSAs), tribal designated statistical areas (TDSAs), state designated tribal statistical areas (SDTSAs), tribal subdivisions, and Hawaiian home lands (HHLs).

These large-scale maps show the boundaries and numbers for all census blocks within an entity. 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 base features, such as roads, railroads and hydrography. The intent of this series is to show each entity on the fewest number of map sheets possible and at the maximum practical scale, depending on the size and shape of the entity and the density of the census blocks it contains. Census block density affects the display of the census blocks numbers and feature identifiers. Each entity 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 entities requiring more than one parent map sheet. The map sheet size is 36 x 32 inches.

Each map is accompanied by a Census Block to Map Sheet relationship file. These semicolon-delimited text files include a record for each census block within the entity, consisting of the corresponding state, county, census tract, and census block codes for the block and a list of all map sheet numbers that the block appears on for that map. When the map entity is a federal American Indian reservation or a tribal subdivision, the Census Block to Map Sheet relationship file also includes the related tribal census tract and tribal block group for each census block.

These county-based reference maps show and label the census tracts as delineated to support 2010 Census data dissemination. These maps also show the boundaries and names of American Indian areas, Alaska Native areas, Hawaiian home lands, counties, county subdivisions, and places. Additionally, these maps display a base feature network including roads, railroads, and water bodies. These features are labeled as map scale permits. The map sheet configuration is optimized to keep the number of map sheets for each county 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 32 inches.

These reference maps show and label the unified, secondary, and elementary school districts as delineated by the state participants of the School District Review Program. These county-based maps also show and label states, counties, and places. Additionally, these maps display a base feature network including roads and water bodies. Major highways and selected water bodies are labeled. 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 school districts 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. For states and state-equivalents, including the District of Columbia, Florida, Hawaii, Maryland, Nevada, and West Virginia, where school districts are coextensive with counties, a state-based map identifying the counties and corresponding school districts is produced. The map sheet size is 36 by 32 inches.