U.S. Census Geographical Hierarchy

Nation

State

County

Tract

Block Group

Census Block Washington

Montana North DakotaMinnesota Maine Oregon New Hampshire Vermont Idaho Wisconsin Michigan South Dakota Massachusetts Wyoming NewYork Rhode Island Connecticut Iowa Nevada Nebraska Indiana P e n n s y lvNew a n Jersey ia Delaware Utah Illinois Maryland California Colorado West District of Columbia Kansas Missouri VirginiaVirginia KentuckyNorth Carolina TennesseeSouth Arizona Oklahoma Carolina NewMexico ArkansasMississippi

AlabamaGeorgia Texas Louisiana

Florida

States and equivalent entities are the primary governmental divisions of the . In addition to the 50 states, the Census Bureau treats the District of Columbia, , , the Commonwealth of the Northern Mariana Hawaii Islands, , and the U.S. Virgin Islands as the statistical equivalents of states for the purpose of data presentation. Utah Colorado Kansas Counties and their equivalents Oklahomaare the primary division of Rio Arriba Colfax Union San Juan Taos states providing complete coverage of a state. In most Mora Los Harding Alamos states, counties are the McKinley Sandoval Santa primary legal division. Fe San Miguel Louisiana has parishes; Alaska Quay Bernalillo has boroughs, and Cibola Guadalupe boroughs, municipalities, and Valencia Torrance Curry census subareas; Maryland, New Mexico Arizona De Baca Missouri, Nevada, and Virginia Socorro Roosevelt Catron have independent in Lincoln addition to counties; Puerto Chaves Rico has municipios; American Sierra Samoa has districts and Grant Lea islands; the Commonwealth of

Otero Eddy the Doña Ana have municipalities; the U.S. Luna Virgin Islands have islands;

Hidalgo and the District of Columbia Texas and Guam are equivalents. Census tracts are small, relatively permanent statistical subdivisions of a county or county equivalent and generally have a population size between 1,200 and 8,000 12.01 people, with an optimum size of 4,000 people. The Census 1.04 Bureau created census tracts 1.03 1.02 to provide a stable set of 2.02 3 4.02 boundaries for statistical 4.01 5 12.03 comparison from census to 12.05 6 7 2.01 census. Census tracts 8 9 occasionally split due to 10 11.02 12.04 population growth or merge when there is substantial

11.03 population decline. Local 11.04 governments have the opportunity to review boundaries prior to each decennial census through the Participant Statistical Areas Program. Census Tract Census 12.01 Tract 12.01 groups are statistical Tract 4.02 divisions of census tracts and generally contain between 600 and 3,000 Census Tract people. Local participants 1 12.03 delineate most block groups 2 prior to each decennial census through the Participant Statistical Areas

Census Program. Since block Census 3 Tract 7 Tract 6 groups consist of a cluster of census blocks, they control block numbering. At the 6 time of block delineation, all 5 of the blocks that fall within a block group will start with Censusthe same number. For 4 Tract 12.05example, census blocks Census 2001, 2002, 2003, … 2999 Tract 9 Census Tract 8 in census tract 1310.02 belong to block group 2. Block Group 2 Block Group 1 Census Blocks are the smallest Block Group 3 geographic areas that the Census Bureau uses to tabulate decennial data. Blocks Block 5001 Block Group 6 Block 5000 are statistical areas bounded Block 5002 by visible features, such as streets, roads, streams, and Block 5003 railroad tracks, and by

Block 5004 Block nonvisible boundaries, such as 5005 selected property lines and Block Block Block Group 5 5007 city, township, , 5006 Block and county limits. Generally, Block 5010 5011 census blocks are small in area; for example, a block in a city bounded on all sides by streets. Census blocks cover Block Group 4 Block 5008 the entire territory of the Block United States, Puerto Rico, 5012 Block and the Island Areas. Census 5009 blocks nest within all other tabulated census geographic entities and are the basis for all tabulated data. United States Geography Statistical Data Geography Statistical Data Level Geography Type Geography Type Name Available Name Available

1 Nation Administrative Housing/Population

2 State Administrative Housing/Population

3 County Administrative Housing/Population

4 Tract Statistical Housing/Population

5 Block Group Statistical Housing/Population

6 Block Statistical For collection only