10,000+ results returned
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Title: United States Census Urbanized Areas, 2008
Contributors:- Polygon data
- 2008
Summary: United States Census Urbanized Areas is a polygon theme representing the Census 2000 Urbanized Areas (UA) and Urban Clusters (UC). A UA consists of contiguous, densely settled census block groups (BGs) and census blocks that meet minimum population density requirements (1000ppsm /500ppsm), along with adjacent densely settled census blocks that together encompass a population of at least 50,000 people. A UC consists of contiguous, densely settled census BGs and census blocks that meet minimum population density requirements, along with adjacent densely settled census blocks that together encompass a population of at least 2,500 people, but fewer than 50,000 people. The dataset covers the 50 States plus the District of Columbia within United States. Attribute information includes a variety of demographic variables from the 2000 U.S. Census. This dataset is a part of the 2008 ESRI Data & Maps collection.
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Title: U.S. 107th Congressional Districts 2002
Contributors:- Polygon data
- 2001
Summary: U.S. 107th Congressional Districts represents political boundaries for the U.S. 107th Congressional Districts.
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Title: U.S. 106th Congressional Districts
Contributors:- Polygon data
- 2000
- Department of Commerce, Census Bureau, Geography Division
- Harvard Geospatial Library
- Environmental Systems Research Institute, Inc. (ESRI)
Summary: U.S. 106th Congressional Districts represents political boundaries for the U.S. 106th Congressional Districts.
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Title: U.S. 106th Congressional Districts 2000
Contributors:- Polygon data
- 1999
Summary: U.S. 106th Congressional Districts represents political boundaries for the U.S. 106th Congressional Districts.
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Title: United States Census Urbanized Areas, 2012
Contributors:- Polygon data
- 2000
- Department of Commerce, Census Bureau, Geography Division
- Environmental Systems Research Institute (Redlands, Calif.)
Summary: United States Census Urbanized Areas is a polygon theme representing the Census 2000 Urbanized Areas (UA) and Urban Clusters (UC). A UA consists of contiguous, densely settled census block groups (BGs) and census blocks that meet minimum population density requirements (1000ppsm /500ppsm), along with adjacent densely settled census blocks that together encompass a population of at least 50,000 people. A UC consists of contiguous, densely settled census BGs and census blocks that meet minimum population density requirements, along with adjacent densely settled census blocks that together encompass a population of at least 2,500 people, but fewer than 50,000 people. The dataset covers the 50 States plus the District of Columbia within United States.
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Title: U.S. Census Urban Areas, 2013
Contributors:- Polygon data
- 2013
Summary: U.S. Census Urban Areas represents the 2010 Census urban areas in the United States. An urban area comprises a densely settled core of census tracts and/or census blocks that meet minimum population density requirements, along with adjacent territory containing non-residential urban land uses as well as territory with low population density included to link outlying densely settled territory with the densely settled core. To qualify as an urban area, the territory identified according to criteria must encompass at least 2,500 people, at least 1,500 of which reside outside institutional group quarters. The U.S. Census Bureau identifies two types of urban areas—Urbanized Areas (UA) of 50,000 or more people and Urban Clusters (UC) of at least 2,500 and less than 50,000 people. The U.S. Census Bureau delineates urban areas that represent densely developed territory, encompassing residential, commercial, and other non-residential urban land uses. In general, this territory consists of areas of high population density and urban land use resulting in a representation of the "urban footprint."
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Title: U.S. Census Urbanized Areas, 2013
Contributors:- Polygon data
- 2010
Summary: U.S. Census Urbanized Areas represents the 2010 Census urban areas in the United States. An urban area comprises a densely settled core of census tracts and/or census blocks that meet minimum population density requirements, along with adjacent territory containing non-residential urban land uses as well as territory with low population density included to link outlying densely settled territory with the densely settled core. To qualify as an urban area, the territory identified according to criteria must encompass at least 2,500 people, at least 1,500 of which reside outside institutional group quarters. The U.S. Census Bureau identifies two types of urban areas—Urbanized Areas (UA) of 50,000 or more people and Urban Clusters (UC) of at least 2,500 and less than 50,000 people. The U.S. Census Bureau delineates urban areas that represent densely developed territory, encompassing residential, commercial, and other non-residential urban land uses. In general, this territory consists of areas of high population density and urban land use resulting in a representation of the "urban footprint."
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Title: New York City ZIP Code Tabulation Areas (ZCTA5), 2008
Contributors:- Polygon data
- 2008
Summary: New York City ZIP Code Tabulation Areas (ZCTA5) is a polygon theme representing zip code areas in New York City.
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Title: New York City Elementary School Districts, 2008
Contributors:- Polygon data
- 2008
Summary: New York City Elementary School Districts, 2008 is a polygon theme representing elementary school districts in New York City in 2008.
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Title: Census Blocks, 2000 - San Francisco Bay Area, California
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: The polygons in this data layer represent U.S. Census Blocks for the San Francisco Bay Area in California. These data have been clipped to the shoreline for cartographic representation. Census blocks are statistical areas bounded on all sides by visible features such as streets, roads, streams, and railroad tracks, and by invisible boundaries such as city, town, township, and county limits, and short imaginary extensions of streets and roads. Generally census blocks are small in area; for example, a block in a city bounded by streets. However, census blocks in remote areas may be large and irregular and contain hundreds of square miles. All territory in the United States, Puerto Rico, and the Island Areas have block numbers. Blocks are composed of one or more GT-polygons; that is, several GT-polygons can share the same block number. Census 2000 Block Numbers. Census 2000 tabulation blocks are numbered uniquely within each state/county/census tract with a four-digit census block number. The U.S. Census Bureau created the tabulation block numbers immediately before beginning its Census 2000 data tabulation process, thereby eliminating block suffixes. The first digit of the tabulation block number identifies the block group. For the 1990 census, the U.S. Census Bureau assigned a unique 1990 block number with a suffix of "Z" to identify crews-of-vessels population. For Census 2000, crews-of-vessels population is assigned to the land block identified by the U.S. Census Bureau as associated with the home port of the vessel. Water Blocks. The U.S. Census Bureau introduced a different method for identifying the water areas of census blocks for Census 2000. For the 1990 census, water was not uniquely identified within a census block; instead, all water area internal to a block group was given a single block number ending in "99" (for example, in block group 1, all water was identified as block 199). A suffix was added to each 1990 water block number where the block existed in more than one tabulation entity within its block group. For Census 2000, water area located completely within the boundary of a single land block has the same block number as that land block. Water area that touches more than one land block is assigned a unique block number not associated with any adjacent land block. The U.S. Census Bureau assigned water block numbers beginning with the block group number followed by "999 " and preceding in descending order. For example, in block group 3, the block numbers assigned to water areas that border multiple land blocks are 3999, 3998, 3997, and so forth. Because some land blocks include water (ponds and small lakes), no conclusions about whether or not a block is all land or all water can be made by looking at the Census 2000 block numbers. Data users must use the WATER field on Record Type S to determine if the GT-polygon is land or water. The WATER field has two values, 0 for land or 1 for water. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). Census Blocks, 2000 - San Francisco Bay Area, California. MTC. Available at: http://purl.stanford.edu/ts501wk9853. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: Census Counties, 2000 - San Francisco Bay Area, California
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: This polygon shapefile displays the 9 counties for the San Francisco Bay Area of California, as of January 1, 2000. The primary legal divisions of most states are termed ''counties.'' Each county and statistically equivalent entity is assigned a three-digit Federal Information Processing Standards code that is unique within the state. These codes are assigned in alphabetical order of county or county equivalent within each state.This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). Census Counties, 2000 - San Francisco Bay Area, California. MTC. Available at: http://purl.stanford.edu/hv237bh9962. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: 2000 Census Traffic Analysis Zones - San Francisco Bay Area, California
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: This polygon shapefile contains the traffic analysis zones (TAZs) for the San Francisco Bay Area in California. These data have been clipped to the shoreline for cartographic representation. TAZs are special-purpose geographic entities delineated by state and local transportation officials for tabulating traffic related data from the decennial census, especially journey-to-work and place-of-work statistics. A TAZ usually consists of one or more census blocks, block groups, or census tracts. Each TAZ is identified by a 6-character alphanumeric census code that is unique within county or statistically equivalent entity. A code of ZZZZZZ indicates a portion of a county where no TAZs were defined. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). 2000 Census Traffic Analysis Zones - San Francisco Bay Area, California. MTC. Available at: http://purl.stanford.edu/tm960wp6354. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: Census Blocks, 2000 - San Francisco Bay Area, California
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: This polygon shapefile represents U.S. Census Blocks for the San Francisco Bay Area of California as of the year 2000. Census blocks are statistical areas bounded on all sides by visible features such as streets, roads, streams, and railroad tracks, and by invisible boundaries such as city, town, township, and county limits, and short imaginary extensions of streets and roads. Generally census blocks are small in area; for example, a block in a city bounded by streets. However, census blocks in remote areas may be large and irregular and contain hundreds of square miles. All territory in the United States, Puerto Rico, and the Island Areas have block numbers. Blocks are composed of one or more GT-polygons; that is, several GT-polygons can share the same block number. Census 2000 Block Numbers. Census 2000 tabulation blocks are numbered uniquely within each state/county/census tract with a four-digit census block number. The U.S. Census Bureau created the tabulation block numbers immediately before beginning its Census 2000 data tabulation process, thereby eliminating block suffixes. The first digit of the tabulation block number identifies the block group. For the 1990 census, the U.S. Census Bureau assigned a unique 1990 block number with a suffix of "Z" to identify crews-of-vessels population. For Census 2000, crews-of-vessels population is assigned to the land block identified by the U.S. Census Bureau as associated with the home port of the vessel. Water Blocks. The U.S. Census Bureau introduced a different method for identifying the water areas of census blocks for Census 2000. For the 1990 census, water was not uniquely identified within a census block; instead, all water area internal to a block group was given a single block number ending in "99" (for example, in block group 1, all water was identified as block 199). A suffix was added to each 1990 water block number where the block existed in more than one tabulation entity within its block group. For Census 2000, water area located completely within the boundary of a single land block has the same block number as that land block. Water area that touches more than one land block is assigned a unique block number not associated with any adjacent land block. The U.S. Census Bureau assigned water block numbers beginning with the block group number followed by "999 " and preceding in descending order. For example, in block group 3, the block numbers assigned to water areas that border multiple land blocks are 3999, 3998, 3997, and so forth. Because some land blocks include water (ponds and small lakes), no conclusions about whether or not a block is all land or all water can be made by looking at the Census 2000 block numbers. Data users must use the WATER field on Record Type S to determine if the GT-polygon is land or water. The WATER field has two values, 0 for land or 1 for water. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). Census Blocks, 2000 - San Francisco Bay Area, California. MTC. Available at: http://purl.stanford.edu/rv407ym2175. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: Census Landmark Polygon Features, 2000 - San Francisco Bay Area, California
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: This polygon shapefile displays landmark features throughout the San Francisco Bay Area in California. "Landmark" is the general name given to a cartographic (or locational) landmark, a land-use area, and a key geographic location (KGL). A cartographic landmark is identified for use by an enumerator while working in the field. A land-use area is identified in order to minimize enumeration efforts in uninhabited areas or areas where human access is restricted. A key geographic location is identified in order to more accurately geocode and enumerate a place of work or residence. The predominant feature classes represented in this layer include airports or airfields, cemeteries, fraternities or sororities, state or local parks or forests, golf courses, lookout towers, educational and religious institutions. Other possible landmark features could include military installations, multi-household or transient quarters, custodial facilities, other types of transportation facilities or terminals, employment centers, open space and other special landmark designations for post offices, police stations and firehouses. The Census Bureau includes landmarks in the Census TIGER data base for locating special features and to help enumerators during field operations. The Census Bureau added landmark features on an as-needed-basis and made no attempt to ensure that all instances of a particular feature were included. The absence of a landmark does not mean that the living quarters, e.g., hospitals and group quarters associated with the landmark were excluded from the 1990 enumeration. A census feature class code (CFCC) is used to identify the most noticeable characteristic of a feature. The CFCC is applied only once to a chain or landmark with preference given to classifications that cover features that are visible to an observer and a part of the ground transportation network. Thus, a road that also is the boundary of a town would have a CFCC describing its road characteristics, not its boundary characteristics. The CFCC, as used in the TIGER/Line files, is a three-character code. The first character is a letter describing the feature class; the second character is a number describing the major category; and the third character is a number describing the minor category. Landmark (Feature Class D) is the general name given to a cartographic (or locational) landmark, a land-use area, and a key geographic location. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). Census Landmark Polygon Features, 2000 - San Francisco Bay Area, California. MTC. Available at: http://purl.stanford.edu/mw173fz6932. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: Census Counties, 2000 - San Francisco Bay Area, California (Clipped)
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: This polygon shapefile displays the boundaries for the 9 counties of the San Francisco Bay Area in California as of January 1, 2000. These data have been clipped to the shoreline for cartographic representation. The primary legal divisions of most states are termed ''counties.'' Each county and statistically equivalent entity is assigned a three-digit Federal Information Processing Standards (FIPS) code that is unique within the state. These codes are assigned in alphabetical order of county or county equivalent within each state. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). Census Counties, 2000 - San Francisco Bay Area, California (Clipped). MTC. Available at: http://purl.stanford.edu/xv509rh6426. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: Census Places, 1990 - San Francisco Bay Area, California (Clipped)
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: This polygon shapefile contains the Census places for the San Francisco Bay Area based as of January 1, 2000. These data have been clipped to the shoreline for cartographic representation. Places, for the reporting of decennial census data, include census designated places, consolidated cities, and incorporated places. Each place is assigned a five-digit Federal Information Processing Standards (FIPS) code. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). Census Places, 1990 - San Francisco Bay Area, California. MTC. Available at: http://purl.stanford.edu/th890tz9933. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: Census Block Groups, 2000 - San Francisco Bay Area, California
Contributors:- Polygon data
- 2002
- California. Metropolitan Transportation Commission
- U.S. Department of Commerce, Bureau of the Census, Geography Division
Summary: This polygon shapefile displays U.S. Census Block Groups for the San Francisco Bay Area in California as of January 1, 2000. Block Groups (BGs) are clusters of blocks within the same census tract having the same first digit of their 4-digit census block number. For example, block group 3 (BG 3) within a census tract includes all blocks numbered from 3000 to 3999. Census 2000 BGs generally contain between 600 and 3,000 people, with an optimum size of 1,500 people. Most BGs were delineated by local participants in the U.S. Census Bureau's Participant Statistical Areas Program. The U.S. Census Bureau delineated BGs only where a local or tribal government declined to participate or where the U.S. Census Bureau could not identify a potential local participant.A BG usually covers a contiguous area. Each census tract contains at least one BG and BGs are uniquely numbered within census tract. Within the standard census geographic hierarchy BGs never cross county or census tract boundaries, but may cross the boundaries of county subdivisions, places, urbanized areas, voting districts, congressional districts, and American Indian/Alaska Native areas/Hawaiian home lands. Under the Census 2000 American Indian/Alaska Native area/Hawaiian homeland census geographic hierarchy, census tracts and BGs are defined within American Indian entities and can cross state and county boundaries. These are commonly referred to as Tribal BGs.BGs have a valid range of 0 through 9. BGs beginning with a 0 generally are in coastal and Great Lakes water and territorial seas. Rather than extending a census tract boundary into the Great Lakes or out to the three mile territorial sea limit, the U.S. Census Bureau delineated some census tract boundaries along the shoreline or just offshore. The U.S. Census Bureau assigned a default census tract number of 0000 and BG of 0 to the offshore areas not included in regularly numbered census tract areas.In decennial census data tabulations, a block group may be split to present data for every unique combination of county subdivision, place, voting district, congressional district, American Indian area/Alaska Native area/ Hawaiian home land shown in the data tabulation products. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data. California, Metropolitan Transportation Commission. (2002). Census Block Groups, 2000 - San Francisco Bay Area, California. MTC. Available at: http://purl.stanford.edu/nk081sx0125. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
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Title: UA Census Miscellaneous Ground Transportation Features, 2000 - California
Contributors:- Line data
- 2002
Summary: This datalayer displays miscellaneous ground transportation features in the state of California. Features other than roads or railroads may be included in this layer. The predominant feature in this layer has a Census Feature Class Code (CFCC) of C20 -- which is classed as power transmission lines. Other features that may be included are: Pipelines: enclosed pipe, carrying fluid or slurry, situated above ground, or in special conditions, below ground when marked by a cleared right-of way and signage. Power Transmission Line: High voltage electrical line, on towers, situated on cleared right-of-way. Miscellaneous Ground Transportation With Special Characteristics: A portion of a ground transportation system that has separately identifiable characteristics. This category is for specialized transportation, usually confined to a local area, that is separate from other ground transportation. Other ground transportation that is not a pipeline or a power transmission line, such as aerial tramway, monorail, or ski lift.
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Title: UA Census Key Geographic Locations, 2000 - Iowa
Contributors:- Polygon data
- 2002
Summary: This datalayer displays Key Geographic Locations (KGLs), as defined by the US Census Bureau, throughout the state. Essential attribute data included are KGL Name and Census Feature Class Code (CFCC). Predominant features represented in this layer include: Airports or airfields; Custodial Facility (hospital, orphanage, Federal penitentiary, state prison); Educational or Religious Institution (convent or monastery, educational institution, religious institution); Multihousehold or Transient Quarters (apartment buildings and complexes, trailer courts or mobile home parks, campground, hotels, motels); Shopping centers or major retail centers; Transportation Terminal (train station, bus or marine terminal). Please note that many other feature types may be present in this layer. Key geographic locations (KGLs) represent a special class of address information. They provide a geocoding tool like address ranges, but also identify a spatial object similar to a landmark. The Census Bureau uses KGLs to identify named buildings where the use of the feature name enhances the ability to geocode addresses. These cases include airports, shopping centers, schools, condominiums, hotels, and apartment complexes. Even though the KGLs appear to identify specific structures, the KGL descriptions do not include location coordinates. In most cases, the Census Bureau can determine the general location of the KGL, but cannot provide a specific location with any certainty. The Census Bureau includes landmarks in the Census TIGER data base for locating special features and to help enumerators during field operations. The Census Bureau added landmark features on an as-needed-basis and made no attempt to ensure that all instances of a particular feature were included. The absence of a landmark does not mean that the living quarters, e.g., hospitals and group quarters associated with the landmark were excluded from the 1990 enumeration. A landmark can be a point, line, or area type. In some cases, the Census TIGER data base permits a choice of types. For instance, an airport or airfield might appear as a point, line, or area; the approach depends on the size of the feature and the depiction of the feature in the source document. Line features such as airfields could appear as one or more complete chains; they are not identified in the landmark record types A census feature class code (CFCC) is used to identify the most noticeable characteristic of a feature. The CFCC is applied only once to a chain or landmark with preference given to classifications that cover features that are visible to an observer and a part of the ground transportation network. Thus, a road that also is the boundary of a town would have a CFCC describing its road characteristics, not its boundary characteristics. The CFCC, as used in the TIGER/Line files, is a three-character code. The first character is a letter describing the feature class; the second character is a number describing the major category; and the third character is a number describing the minor category. Landmark (Feature Class D) is the general name given to a cartographic (or locational) landmark, a land-use area, and a key geographic location. A cartographic landmark is identified for use by an enumerator while working in the field. A land-use area is identified in order to minimize enumeration efforts in uninhabited areas or areas where human access is restricted. A key geographic location is identified in order to more accurately geocode and enumerate a place of work or residence.
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Title: UA Census Block Groups, 2000 - West Virginia
Contributors:- Polygon data
- 2002
Summary: The polygons represent U.S. Census Block Groups for the state based on the ground condition of January 1, 2000. Block Groups (BGs) are clusters of blocks within the same census tract having the same first digit of their 4-digit census block number. For example, block group 3 (BG 3) within a census tract includes all blocks numbered from 3000 to 3999. Census 2000 BGs generally contain between 600 and 3,000 people, with an optimum size of 1,500 people. Most BGs were delineated by local participants in the U.S. Census Bureau's Participant Statistical Areas Program. The U.S. Census Bureau delineated BGs only where a local or tribal government declined to participate or where the U.S. Census Bureau could not identify a potential local participant. A BG usually covers a contiguous area. Each census tract contains at least one BG and BGs are uniquely numbered within census tract. Within the standard census geographic hierarchy BGs never cross county or census tract boundaries, but may cross the boundaries of county subdivisions, places, urbanized areas, voting districts, congressional districts, and American Indian/Alaska Native areas/Hawaiian home lands. Under the Census 2000 American Indian/Alaska Native area/Hawaiian homeland census geographic hierarchy, census tracts and BGs are defined within American Indian entities and can cross state and county boundaries. These are commonly referred to as Tribal BGs. BGs have a valid range of 0 through 9. BGs beginning with a 0 generally are in coastal and Great Lakes water and territorial seas. Rather than extending a census tract boundary into the Great Lakes or out to the three mile territorial sea limit, the U.S. Census Bureau delineated some census tract boundaries along the shoreline or just offshore. The U.S. Census Bureau assigned a default census tract number of 0000 and BG of 0 to the offshore areas not included in regularly numbered census tract areas. In decennial census data tabulations, a block group may be split to present data for every unique combination of county subdivision, place, voting district, congressional district, American Indian area/Alaska Native area/ Hawaiian home land shown in the data tabulation products.