Welcome to the Census Bureau's Participant Statistical Areas Program web page. At this site you can review the Census 2000 boundary criteria that will be used to define census tracts, census block groups (BGs), census county divisions (CCDs), and census designated places (CDPs) for the Census 2000 Participant Statistical Areas Program. Beginning in March 1998, the Census Bureau began working with local participants to delineate their statistical areas according to the criteria provided. A formal and more detailed description of these criteria were published in the Federal Register Notice. For more information, please refer to the appropriate Federal Register citation listed at the end of each section.
The Participant Statistical Areas Program guidelines [PDF] provide participants with detailed instructions and assistance in submitting specific statistical areas as part of the Census 2000 Participant Statistical Areas Program. Please review all guidelines in which you are interested when submitting plans. If you would like a hard copy of these guidelines, please contact your local Regional Office.
If you have any questions regarding the criteria for the Participant Statistical Areas Program or the program guidelines, please contact Mike Ratcliffe, Geography Division, at (301) 763-3056, by e-mail at michael.r.ratcliffe@census.gov or by mail to Geography Division, U.S. Census Bureau, Washington, DC, 20233-7400.
When sending comments by e-mail, please include a telephone number, street address, and professional/organizational affiliation.
For more information about the Census Bureau's statistical areas, geographic concepts or terminology, please reference the Geographic Areas Reference Manual, published by the U.S. Census Bureau.
Census tracts are small, relatively permanent geographic subdivisions of a county or equivalent entity. The primary purpose of census tracts is to provide a nationwide set of geographic units that have stable boundaries. For Census 2000, the Census Bureau will work with local participants to delineate census tracts for the entire United States, Puerto Rico, and the Island Areas (American Samoa, Guam, the Northern Mariana Islands, and the Virgin Islands of the United States).
Each census tract must constitute a reasonably compact, continuous land area, all parts of which are internally accessible by road. The entire area and population of a county are covered by census tracts. Census tracts are identified by four-digit numbers ranging from 0001 to 9989; a two-digit decimal suffix also may be used. Census tract numbers can NOT be used more than once in a county. Population size criteria for census tracts are:
| Population Thresholds | |||
|---|---|---|---|
| Area(s) | Optimum | Minimum | Maximum |
| United States, Puerto Rico, Virgin Islands of the U.S. | 4,000 | 1,500 | 8,000 |
| Island Areas (American Samoa, Guam, Northern Mariana islands) | 2,500 | 1,500 | 8,000 |
| American Indian Reservation | 2,500 | 1,000 | 8,000 |
| *Special place census tract | none | 1,000 | none |
* Special places are correctional institutions, military installations, college campuses, workers' dormitories, hospitals, nursing homes, and group homes.
Census tract boundaries should follow visible and identifiable features, such as roads, rivers, canals, railroads, and above-ground high-tension power lines. The following nonvisible, governmental unit boundaries are acceptable as census tract boundaries: All state and county boundaries.
Apart from the combination of the BNA program with the census tract program, most provisions of the census tract criteria remain unchanged from 1990. For more information about the Census Tract Program please see the Notice of Final Program: Federal Register, (October 28, 1997) for more information. Back to Top
Block groups are geographic subdivisions of census tracts; their primary purpose is to provide a geographic summary unit for census block data. A block group must comprise a reasonably compact and contiguous cluster of census blocks. Each census tract contains a minimum of one block group and may have a maximum of nine block groups.
Within a census tract, a block group consists of all census blocks whose numbers begin with the same digit. For example in 1990, block group 3 included all census blocks numbered in the 300s. For Census 2000 the Census Bureau will introduce a four-digit block numbering system, and block group 3 will include all census blocks numbered in the 3000s within a census tract.
The Census Bureau will work with local participants to delineate block groups in the United States, Puerto Rico, and the Island Areas (American Samoa, Guam, the Northern Mariana Islands, and the Virgin Islands of the United States). Population size criteria for block groups are:
| Population Thresholds | |||
|---|---|---|---|
| Area(s) | Optimum | Minimum | Maximum |
| Standard | 1,500 | 600 | 3,000 |
| American Indian Reservation | 1,000 | 300 | 3,000 |
| *Special place | none | 300 | none |
* Special places are correctional institutions, military installations, college campuses, workers' dormitories, hospitals, nursing homes, and group homes.
Block group boundaries should follow visible and identifiable features, such as roads, rivers, canals, railroads, and above-ground high-tension power lines. Census tract boundaries are always block group boundaries. The following nonvisible governmental unit boundaries are acceptable as block group boundaries:
When satisfactory features are not available, the Census Bureau may at its discretion approve other nonstandard visible features, such as ridge lines, pipelines, intermittent streams, fence lines, boundaries of National Parks and National Forests, military reservations, cemeteries or other special land-use properties, and the straight-line extensions of visible features or other lines of sight.
Except as noted above, most provisions of the block group criteria remain unchanged from 1990.
For more information about the Census Block Group Program please see the Notice of Final Program: Federal Register, (January 9, 1998) for more information. Back to Top
Census county divisions (CCDs) are geographic statistical subdivisions of counties established cooperatively by the Census Bureau and officials of state and local governments in states where minor civil divisions (MCDs) either do not exist or are unsatisfactory for census purposes.
There are CCDs in 21 states: Alabama, Arizona, California, Colorado, Delaware, Florida, Georgia, Hawaii, Idaho, Kentucky, Montana, Nevada, New Mexico, Oklahoma, Oregon, South Carolina, Tennessee, Texas, Utah, Washington, and Wyoming.
The primary goal of delineating CCDs is to establish and maintain a set of subcounty units that have stable boundaries and recognizable names. A CCD usually represents one or more communities, trading centers or, in some instances, major land uses. It usually consists of a single geographic piece that is relatively compact in shape. The geographic "building blocks" of CCDs are census tracts, and many CCDs are groupings of several contiguous census tracts.
New CCDs for Census 2000 should have a minimum population of 1,500 persons. Some existing CCDs may have smaller populations. There is no maximum population size limit for a CCD. A CCD name often is the same as that of the largest population center or place within the county. Sometimes it may represent two large centers; for example, Bayard-Santa Rita. Or it may be the name of a prominent physical feature (Castle Rock) or a distinctive region (Death Valley). Some CCD names consist of a name and a compass direction, such as Northwest Union or Smithville North. In all cases, CCD names should be meaningful to data users.
CCD boundaries should follow visible, permanent, identifiable features such as roads, rivers, canals, railroads, and above-ground high-tension power lines. The following nonvisible governmental unit boundaries are acceptable as CCD boundaries:
In very rural counties with distinctive geographic regions, two or more CCDs may "nest" within one census tract, and may have populations less than the minimum permissible for a census tract (1,500 persons).
For more information about the Census County Division Program please see the Notice of Final Program: Federal Register, (January 9, 1998). Back to Top
Census designated places (CDPs) are closely settled, named, unincorporated communities that generally contain a mixture of residential, commercial, and retail areas similar to those found in incorporated places of similar sizes. The Census Bureau works with local participants to delineate boundaries for CDPs. By defining CDPs, the Census Bureau can tabulate and disseminate data for localities that otherwise would not be identified as places in the decennial census data products.
Each CDP will contain an identifiable core encompassing the area that is associated strongly with the CDP name and contains the majority of the CDP's population, housing, commercial structures, and economic activity. A CDP must comprise a reasonably compact and continuous land area internally accessible to all points by road. (Except where parts of a CDP are separated by a narrow corridor of incorporated territory, or where the topography or geographic patterns of settlement are not compact, but are irregularly shaped.) A CDP may not be located partially or entirely within an incorporated place or another CDP. A CDP encompasses the surrounding closely settled territory associated with the place name. The Census Bureau does not intend for a CDP to be an apartment complex or residential subdivision in densely settled areas or simply a crossroads in rural areas.
There are no minimum or maximum population thresholds for recognition as a CDP. This represents a substantial change from all prior CDP criteria.
A CDP name may not duplicate the name of an adjacent or nearby incorporated place.
A CDP may not be located in more than one state, nor may a CDP cross the boundaries of American Indian reservations (AIRs), American Indian trust lands, or a Tribal Jurisdiction Statistical Areas (TJSA)s. A CDP, however, may cross county and county subdivision boundaries.
A CDP may not be coextensive with Alaska Native village statistical areas (ANVSA), county subdivisions, counties, AIRs, TJSAs, and states. (Exceptions are: Arlington County, Virginia, towns in New England, townships in New Jersey and Pennsylvania, and charter townships in Michigan.
CDP boundaries should follow visible and identifiable features, such as roads, rivers, canals, railroads, and above-ground high-tension power lines. The following nonvisible governmental unit boundaries are acceptable as CDP boundaries:
The Census Bureau may modify, and if necessary reject, any proposed CDP that does not comply with the CDP criteria. The Census Bureau also may define CDPs in instances where clear evidence of a place exists, but for which local participating officials did not submit boundaries.
For more information about the Census Designated Place Program please see the Notice of Final Program: Federal Register, (August 22, 1997) for more information.
If you have any questions regarding the criteria for the Participant Statistical Areas Program, please contact Mike Ratcliffe, Geography Division, at (301) 763-3056, by e-mail at Michael.R.Ratcliffe@census.gov , or by mail to Geography Division, U.S. Census Bureau, Washington, DC, 20233-7400.
When sending comments by e-mail, please include a telephone number, street address, and your professional/organizational affiliation.
For more information about the Census Bureau's statistical areas, geographic concepts or terminology, please reference the Geographic Areas Reference Manual, published by the U.S. Census Bureau. Back to Top
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