Census 2000 TIGER/Line(R) Files Technical Documentation Chapter 4: Geographic Entities Overview The Census 2000 TIGER/Line(R) files contain the boundaries of legal and statistical entities. The boundaries of the legal entities contained in the Census 2000 TIGER/Line files are those reported to the U.S. Census Bureau to be legally in effect on January 1, 2000. It is important to note that the boundary information in the TIGER/Line files for both legal and statistical entities are for U.S. Census Bureau statistical data collection and tabulation purposes only; their depiction and designation for statistical purposes does not constitute a determination of jurisdictional authority or rights of ownership or entitlement. The legal entities shown in the files are: States and their statistical equivalents-Census 2000 and 1990 Counties and their statistical equivalents-Census 2000 and 1990 Minor civil divisions (MCDs)-Census 2000 and 1990 Subbarrios (Puerto Rico only)-Census 2000 only Consolidated cities-Census 2000 only Incorporated places-Census 2000 and 1990 American Indian reservations (both federally and state-recognized)-Census 2000 and 1990 American Indian trust lands-Census 2000 and 1990 American Indian tribal subdivisions-Census 2000 only Alaska Native Regional Corporations-Census 2000 only Hawaiian home lands-Census 2000 only Oregon urban growth areas-Census 2000 only Congressional districts-current only Voting districts-Census 2000 only State legislative districts-Census 2000 only School districts-Census 2000 only The statistical entities included in the files are: Census areas (statistical county equivalents in Alaska)-Census 2000 and 1990 Census county divisions and unorganized territories (statistical county subdivisions)- Census 2000 and 1990 Census designated places (statistical place equivalents)-Census 2000 and 1990 Place (balance) entities (statistical place equivalents within consolidated cities)- Census 2000 and 1990 American Indian/Alaska Native statistical areas 1) Alaska Native village statistical areas-Census 2000 and 1990 2) Tribal designated statistical areas-Census 2000 and 1990 3) Tribal jurisdiction statistical areas-1990 only 4) Oklahoma tribal statistical areas-Census 2000 only 5) State designated American Indian statistical areas-Census 2000 only Census tracts-Census 2000 and 1990 Block numbering areas-1990 only Census block groups-Census 2000 only Census blocks-Census 2000 and 1990 Urban areas-1990 only Metropolitan areas: 1) Consolidated metropolitan statistical areas-Census 2000 only 2) Metropolitan statistical areas-Census 2000 only 3) Primary metropolitan statistical areas-Census 2000 only Traffic analysis zones-Census 2000 only ZIP Code Tabulation Areas (ZCTAs(TM))-Census 2000 only Public Use Microdata Areas-1990 only Geographic entities tabulated by the U.S. Census Bureau generally are hierarchical; that is, in a progression from the Nation to the block level. This hierarchical structure is derived from the legal, administrative, or areal relationships of the entities. The smallest level of census geography is the census block. Census blocks are defined within block groups, block groups are defined within census tracts, census tracts are defined within counties and statistically equivalent entities, counties and statistically equivalent entities are within states and statistically equivalent entities, states and statistically equivalent entities are within the Nation. American Indian areas, Alaska Native areas, and Hawaiian home lands; Metropolitan Areas; Urban Areas; and ZIP Code Tabulation Areas (ZCTAs) are within the Nation and comprised of census blocks. Within states and statistically equivalent entities and comprised of census blocks are Congressional Districts, Alaska Native Regional Corporations (ANRCs), School Districts, Urban Growth Areas (UGAs), State Legislative Districts (SLDs), and Places. Within counties and statistically equivalent entities and comprised of census blocks are County Subdivisions, Voting Districts (VTDs), and Traffic Analysis Zones (TAZs). In Puerto Rico, Subbarrios are within County Subdivisions and are comprised of census blocks. See Appendix F for a count of legal and statistical entities. The TIGER/Line files identify geographic areas using the Federal Information Processing Standard (FIPS) codes or U.S. Census Bureau- assigned codes. The TIGER/Line files depict geographic areas in two ways: The assignment of codes to the left and the right sides of the complete chains (Record Types 1 and 3) The identification of codes that belong to each GT-polygon(Record Types A and S) The TIGER/Line files identify some geographic entities in both the complete chain and polygon records for certain boundary vintages. This chapter provides detailed information on the record types and fields for the geographic entities. Codes for Entities Appendix A is a list of FIPS state and county codes. A list of valid codes and names for other legal entities does not appear in the documentation for the TIGER/Line files. The TIGER/Line files include Record Type C which lists the geographic codes and names plus some attribute data (FIPS 55 class code, census place description code, legal/statistical area description code, and entity type) for certain entities. The codes and names are identified as 1990 or Census 2000. The FIPS Code, Name, and/or Attribute Data Applicable Year field (field name DATAYR) may have three values: 1990 for geographic names and codes valid for the 1990 census, 2000 for Census 2000 geographic names and codes, and blank when the geographic names and codes are same for 1990 and Census 2000. The documentation and paper or file versions of the FIPS codes areavailable for sale from the National Technical Information Service (NTIS), U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161. The telephone number is (703) 605-6000. The U.S. Geological Survey (USGS) maintains the FIPS 55 codes. Information about FIPS codes is available from USGS's Geographic Names Section at (703) 648-4544. The National Institute of Standards and Technology (NIST) maintains an Internet World Wide Web site of FIPS codes and information. The URL for FIPS codes is http://www.census.gov/geo/www/fips/fips.html. The FIPS publications include: FIPS PUB 5-2, Codes for the Identification of the States, the District of Columbia and the Outlying Areas of the United States, and Associated Areas FIPS PUB 6-4, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas FIPS PUB 8-6, Metropolitan Areas (Including MSAs, CMSAs, PMSAs, and NECMAs) FIPS PUB 55-3, Codes for Named Populated Places, Primary County Divisions, and Other Locational Entities of the United States, Puerto Rico, and the Outlying Areas The U.S. Census Bureau uses the codes in FIPS PUB 55-3 to identify both legal and statistical entities for county subdivisions, places, and American Indian areas/Alaska Native areas/Hawaiian home lands. FIPS PUB 55-3 includes many more entity records than those for which the U.S. Census Bureau tabulates data. The FIPS 55 codes are state-based. American Indian reservations, off-reservation trust land areas, American Indian tribal subdivisions, Oklahoma tribal statistical areas, State designated American Indian statistical areas, and/or tribal designated statistical areas in more than one state will have a different FIPS 55 code for each state portion of the single American Indian entity. Entity Type Codes The U.S. Census Bureau uses the Entity Type Code field on Record Type C to identify what type of legal or statistical entity the record, including its FIPS or Census code (American Indian areas/Alaska Native areas/Hawaiian home lands only) and name references. For example, the FIPS codes for both places and county subdivisions appear in the FIPS PUB 55-3 Code field. The Entity Type Code field identifies whether the FIPS code references a place, consolidated city, county subdivision, Alaska Native Regional Corporation, American Indian/Alaska Native Area/Hawaiian home land, or American Indian tribal subdivision. Entity Type Codes Code Geographic Entity Type A Consolidated City C County or Statistically Equivalent Entity I American Indian/Alaska Native Area /Hawaiian Home Land except for Alaska Native Regional Corporation J Metropolitan Area L Subbarrio M County Subdivision P Place S State or Statistically Equivalent Entity T Census Tract U Urban Area V Voting District W Alaska Native Regional Corporation X American Indian Tribal Subdivision Y Oregon Urban Growth Area 3 Unified School District 4 Secondary School District 5 Elementary School District Names for Entities The TIGER/Line files contain not only the codes for geographic entities, but also the geographic entity names. Record Type C links the geographic entity codes appearing in a TIGER/Line file to the name of the geographic entity associated with that code. Multiple records for the same geographic entity may appear in a TIGER/Line file. The FIPS Code, Name, and/or Attribute Data Applicable Year field (field name DATAYR) identifies the names and codes as 1990, Census 2000, or both. Refer to the section on Codes for Entities in this chapter for information on the three possible DATAYR values. Geographic Entities American Indian Areas, Alaska Native Areas, and Hawaiian Home Lands (AIANA/HHL) There are both legal and statistical American Indian, Alaska Native, and native Hawaiian entities for which the U.S. Census Bureau provides data. The legal entities consist of federally recognized American Indian reservations and off- reservation trust land areas, the tribal subdivisions that can divide these entities, state recognized American Indian reservations, Alaska Native Regional Corporations (ANRCs), and Hawaiian home lands (HHLs). The statistical entities are Alaska Native village statistical areas (ANVSAs), Oklahoma tribal statistical areas (OTSAs), tribal designated statistical areas (TDSAs), and state designated American Indian statistical areas (SDAISAs). Tribal subdivisions can exist within the statistical Oklahoma tribal statistical areas. In all cases, these areas are mutually exclusive in that no American Indian, Alaska Native, or Hawaiian home land can overlap another tribal entity, except for tribal subdivisions, which subdivide some American Indian entities, and Alaska Native village statistical areas (ANVSAs), which exist within Alaska Native Regional Corporations (ANRCs). In some cases where more than one tribe claims jurisdiction over an area, the U.S. Census Bureau creates a joint use area as a separate entity to define this area of dual claims. The American Indian areas, Alaska Native areas, and Hawaiian home lands (AIANA/HHLs) are represented in the TIGER/Line files by a 5-character numeric FIPS code field, a 4-character numeric census code field (except for American Indian Tribal subdivisions which have a 3-character numeric census code field), and a single alphabetic character American Indian/Hawaiian home land trust land indicator field. FIPS codes are assigned in alphabetical sequence within state; because of this the FIPS code is different in each state for American Indian entities in more than one state. The census codes are assigned in alphabetical order nationwide, except that joint use areas appear at the end of the code range. The U.S. Census Bureau assigns the 3-character American Indian tribal subdivision code alphabetically in order and unique within each reservation, associated off- reservation trust land, and Oklahoma tribal statistical area (OTSA). The TIGER/Line files use multiple fields to identify the legal and statistical AIANA/HHLs: Legal Entities Alaska Native Regional Corporations (ANRCs) are corporate entities organized to conduct both business and nonprofit affairs for Alaska Natives pursuant to the Alaska Native Claims Settlement Act of 1972 (Public Law 92-203). Twelve ANRCs are geographic entities that cover most of the state of Alaska (the Annette Islands Reserve, an American Indian reservation, is excluded from any ANRC). A thirteenth ANRC represents Alaska Natives who do not live in Alaska and do not identify with any of the 12 corporations. The U.S. Census Bureau does not provide data for this ANRC because it has no geographic extent and it does not appear in the TIGER/Line files. ANRC boundaries have been legally established. The U.S. Census Bureau offers representatives of the 12 nonprofit ANRCs the opportunity to review and update the ANRC boundaries. The U.S. Census Bureau first provided data for ANRCs for the 1990 census. American Indian reservations-Federal (federal AIRs) are areas that have been set aside by the United States for the use of tribes, the exterior boundaries of which are more particularly defined in the final tribal treaties, agreements, executive orders, federal statutes, secretarial orders, or judicial determinations. The U.S. Census Bureau recognizes federal reservations as territory over which American Indian tribes have primary governmental authority. These entities are known as colonies, communities, pueblos, rancherias, ranches, reservations, reserves, villages, Indian communities, and Indian villages. The Bureau of Indian Affairs maintains a list of federally recognized tribal governments. The U.S. Census Bureau contacts representatives of American Indian tribal governments to identify the boundaries for federal reservations. Federal reservations may cross state, county, county subdivision, and place boundaries. The BIA supplied the U.S. Census Bureau with the names and exterior boundaries of the federal AIRs used for the 1990 census. The U.S. Census Bureau first reported data for American Indian reservations in the 1970 census. American Indian reservations-State (state AIRs) are reservations established by some state governments for tribes recognized by the state. A governor- appointed state liaison provides the names and boundaries for state recognized American Indian reservations to the U.S. Census Bureau. State reservations may cross county, county subdivision, and place boundaries. American Indian tribal subdivisions are administrative subdivisions of federally recognized American Indian reservations, off-reservation trust land, or Oklahoma tribal statistical areas (OTSAs). Tribal subdivisions are known as areas, chapters, communities, or districts. These entities are internal units of self-government or administration that serve social, cultural, and/or economic purposes for the American Indians on the reservations, off-reservation trust lands, or OTSAs. The U.S. Census Bureau obtains the boundary and name information for tribal subdivisions from tribal governments. The U.S. Census Bureau first provided data for American Indian tribal subdivisions in 1980 when it identified them as "American Indian subreservation areas." The U.S. Census Bureau did not provide data for American Indian tribal subdivisions in conjunction with the 1990 census. American Indian trust lands are areas for which the United States holds title in trust for the benefit of a tribe (tribal trust land) or for an individual Indian (individual trust land). Trust lands can be alienated or encumbered only by the owner with the approval of the Secretary of the Interior or his/her authorized representative. Trust lands may be located on or off a reservation. The U.S. Census Bureau recognizes and tabulates data for reservations and off-reservation trust lands because American Indian tribes have primary governmental authority over these lands. Primary tribal governmental authority generally is not attached to tribal lands located off the reservation until the lands are placed in trust. In U.S. Census Bureau data tabulations, off-reservation trust lands always are associated with a specific federally recognized reservation and/or tribal government. A tribal government appointed liaison provides the name and boundaries of their trust lands. The Bureau of Indian Affairs (BIA), an agency in the U.S. Department of the Interior, identified and provided maps of these areas for use by the U.S. Census Bureau for the 1990 census. The U.S. Census Bureau first reported data for off-reservation tribal trust lands in the 1980 census; in 1990, the trust land data included both tribal and individual trust lands. The U.S. Census Bureau does not identify fee land (or land in fee simple status) or restricted fee lands as specific geographic categories and they are not identified in the TIGER/Line files. Trust lands are assigned the same code as the reservation with which they are associated. Trust lands associated with tribes that do not have a reservation are assigned codes based on tribal name. In the TIGER/Line files, a letter code-"T" for tribal and "I" for individual-appears in a separate field and identifies off-reservation trust lands. Hawaiian Home Lands (HHLs) are areas held in trust for native Hawaiians by the state of Hawaii, pursuant to the Hawaiian Homes Commission Act of 1920, as amended. Based on a compact between the federal government and the new state of Hawaii in 1959, the Hawaii Admission Act vested land title and responsibility for the program with the state. However, a Hawaiian home land is not a governmental unit; rather, a home land is a tract of land, with a legally defined boundary, that is owned by the state, which, as authorized by the Act, it may lease to one or more native Hawaiians for residential, agricultural, commercial, industrial, pastoral, and any other activities authorized by state law. The U.S. Census Bureau obtains the names and boundaries for Hawaiian home lands from state officials. The names of the home lands are based on the traditional ahupua'a names of the Crown and government lands of the Kingdom of Hawai'i from which the lands were designated, or from the local name for an area. Hawaiian home lands are a new geographic entity for Census 2000. Joint use areas, as applied to any American Indian area/Alaska Native area by the U.S. Census Bureau, means an area that is administered jointly and/or claimed by two or more American Indian tribes. The U.S. Census Bureau designates both legal and statistical joint use areas as unique geographic entities for the purpose of presenting statistical data. Statistical Entities Alaska Native village statistical areas (ANVSAs) represent the densely settled portion of Alaska Native villages (ANVs). The ANVs constitute associations, bands, clans, communities, groups, tribes, or villages recognized pursuant to the Alaska Native Claims Settlement Act of 1972 (Public Law 92-203). Because ANVs do not have boundaries that are easily locatable, the U.S. Census Bureau does not delimit ANVs for the purpose of presenting statistical data. Instead, the U.S. Census Bureau presents statistical data for ANVSAs which represent the settled portion of ANVs. ANVSAs are delineated or reviewed by officials of the ANV or, if no ANV official chose to participate in the delineation process, officials of the Alaska Native Regional Corporation (ANRC) in which the ANV is located. An ANVSA may not overlap the boundary of another ANVSA, an American Indian reservation, or a tribal designated statistical area (TDSA). The U.S. Census Bureau first provided data for ANVSAs for the 1990 census. Joint use areas, as applied to any American Indian area/Alaska Native area by the U.S. Census Bureau, means an area that is administered jointly and/or claimed by two or more American Indian tribes. The U.S. Census Bureau designates both legal and statistical joint use areas as unique geographic entities for the purpose of presenting statistical data. Oklahoma tribal statistical areas (OTSAs) are statistical entities identified and delineated by the U.S. Census Bureau in consultation with federally recognized American Indian tribes that do not currently have a reservation, but once had a reservation in Oklahoma. The boundary of an OTSA will be that of the former reservation in Oklahoma, except where modified by agreements with neighboring tribes for statistical data presentation purposes. OTSA replaces the 1990 census term tribal jurisdiction statistical area (TJSA). The U.S. Census Bureau first provided data for these former reservations in conjunction with the 1980 census, when it defined a single all-encompassing geographic entity called the "Historic Areas of Oklahoma." State designated American Indian statistical areas (SDAISAs) are statistical entities for state recognized American Indian tribes that do not have a state recognized land base (reservation). SDAISAs are identified and delineated for the U.S. Census Bureau by a state liaison identified by the governor's office in each state. SDAISAs generally encompass a compact and contiguous area that contains a concentration of people who identify with a state recognized American Indian tribe and in which there is structured or organized tribal activity. A SDAISA may not be located in more than one state unless the tribe is recognized by both states, and it may not include area within an American Indian reservation, off-reservation trust land, Alaska Native village statistical area (ANVSA), tribal designated statistical area (TDSA), or Oklahoma tribal statistical area (OTSA). The U.S. Census Bureau established SDAISAs as a new geographic statistical area for Census 2000 to differentiate between state recognized tribes without a land base and federally recognized tribes without a land base. For the 1990 census, all such tribal entities had been identified as TDSAs. Tribal designated statistical areas (TDSAs) are statistical entities identified and delineated for the U.S. Census Bureau by federally recognized American Indian tribes that do not currently have a federally recognized land base (reservation or off-reservation trust land). A TDSA generally encompasses a compact and contiguous area that contains a concentration of individuals who identify with a federally recognized American Indian tribe and in which there is structured or organized tribal activity. A TDSA may be located in more than one state, but it may not include area within an American Indian reservation, off-reservation trust land, Alaska Native village statistical area (ANVSA), or Oklahoma tribal statistical area (OTSA). The U.S. Census Bureau first reported data for TDSAs in conjunction with the 1990 census, when both federally and state recognized tribes could identify and delineate TDSAs. For Census 2000, TDSAs now apply only to federally recognized tribes. State recognized tribes without a land base, including those that were TDSAs in 1990, are identified as state designated American Indian statistical areas (SDAISAs), a new geographic entity for Census 2000. Tribal jurisdiction statistical areas (TJSAs) were 1990 statistical entities identified and delineated for the 1990 census to provide a geographic frame of reference for the presentation of statistical data. 1990 TJSA boundaries were required to follow census block boundaries and were based upon the boundaries of the former reservations of federally recognized tribes in Oklahoma. TJSAs replaced the Historic Areas of Oklahoma recognized by the U.S. Census Bureau for the 1980 decennial census. The 1990 descriptive designation, TJSA, has been changed for Census 2000 to Oklahoma tribal statistical areas (OTSAs). AIANA/HHL Code Record Locations Record Type Field Name Description 1 AIANHHL FIPS 55 Code (American Indian/Alaska Native Area/ Hawaiian Home Land), 2000 Left 1 AIANHHR FIPS 55 Code (American Indian/Alaska Native Area/ Hawaiian Home Land), 2000 Right 1 AIHHTLIL American Indian/Hawaiian Home Land Trust Land Indicator, 2000 Left 1 AIHHTLIR American Indian/Hawaiian Home Land Trust Land Indicator, 2000 Right 3 AIANHHCE90L Census Code (American Indian/Alaska Native Area/ Hawaiian Home Land),1990 Left 3 AIANHHCE90R Census Code (American Indian/Alaska Native Area/ Hawaiian Home Land),1990 Right 3 AIHHTLI90L American Indian/Hawaiian Home Land Trust Land Indicator, 1990 Left 3 AIHHTLI90R American Indian/Hawaiian Home Land Trust Land Indicator, 1990 Right 3 AIANHHCEL Census Code (American Indian/Alaska Native Area/ Hawaiian Home Land), 2000 Left 3 AIANHHCER Census Code (American Indian/Alaska Native Area/ Hawaiian Home Land), 2000 Right 3 ANRCL FIPS 55 Code (ANRC), 2000 Left 3 ANRCR FIPS 55 Code (ANRC), 2000 Right 3 AITSCEL Census Code (American Indian Tribal Subdivision), 2000 Left 3 AITSCER Census Code (American Indian Tribal Subdivision), 2000 Right 3 AITSL FIPS 55 Code (American Indian Tribal Subdivision), 2000 Left 3 AITSR FIPS 55 Code (American Indian Tribal Subdivision), 2000 Right A AIANHH90 FIPS 55 Code (American Indian/Alaska Native Area/ Hawaiian Home Land), 1990 A AIANHHCE90 Census Code (American Indian/Alaska Native Area / Hawaiian Home Land), 1990 C ENTITY Entity Type Code C AIANHHCE Census American Indian/Alaska Native Area / Hawaiian Home Land Code C AITSCE Census American Indian Tribal Subdivision Code C NAME Name of Geographic Area S AIANHH FIPS 55 Code (American Indian/Alaska Native Area/ Hawaiian Home Land), 2000 S AIANHHCE Census Code (American Indian/Alaska Native Area / Hawaiian Home Land), 2000 S AIHHTLI American Indian /Hawaiian Home Land Trust Land Indicator, 2000 AIANA/HHL Codes Record Type C shows one record for each AIANA/HHL entity by year. Also, refer to FIPS PUB 55-3 for a list of valid codes and entity names. The type of AIANA/HHL area can be identified either by the census code or by the FIPS 55 class code on each entity record in Record Type C. The range of census codes allocated to each AIANA/HHL and the valid FIPS 55 class code(s) associated with each are as follows: Type Census Code Range - 2000 Valid FIPS 55 Class Federal AIR 0001 to 4999 D1, D2, D3 Hawaiian Home Land 5000 to 5499 F1 OTSA 5500 to 5999 D6 ANVSA 6000 to 7999 E1, E2, E6 TDSA 8000 to 8999 D6 State AIR 9000 to 9499 D4 SDAISA 9500 to 9999 D9 Type Census Code Range - 1990 Valid FIPS 55 Class AIR 0001 to 4989 D1, D2, D3, D4, D5 TJSA 5000 to 5989 D6 ANVSA 6000 to 8989 E1, E2, E6 TDSA 9000 to 9989 D6 Type Trust Land Indicator Hawaiian Home Land H Individual Trust Land I Tribal Trust Land T Block Groups (BGs) Block groups are clusters of blocks within the same census tract having the same first digit of their 4-digit census block number. For example, blocks 3001, 3002, 3003, . . ., 3999 in census tract 1210.02 belong to BG 3. 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 home land 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. Block Group Number Record Locations Record Type Field Name Description S BLKGRP Census Block Group, 2000 All polygons have a non-blank BG number. The left- and right-side complete chain block numbers should not be blank except where they are located along the outside edge of the county boundary. The TIGER/Line files do not contain codes for areas outside the county file. Census Blocks 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. To improve operational efficiency and geographic identifications for Census 2000, the U.S. Census Bureau introduced different numbering systems for tabulation blocks, used in the census data products, and for collection blocks, used in administering the census. In 1990 the U.S. Census Bureau used a single block numbering system and appended an alphabetic suffix to the basic number where a collection block was split by a tabulation boundary. Tabulation blocks, used in Census 2000 data products, never cross county or census tract boundaries. Nor do they cross the boundaries of any entity for which the U.S. Census Bureau tabulates data including American Indian areas, Alaska Native areas, Hawaiian home lands, congressional districts, county subdivisions, military installations, national parks and monuments, places, state legislative districts, urban and rural areas, urbanized areas, school districts, voting districts, or ZIP Code Tabulation Areas (ZCTAs). Census 2000 used a set of collection geographic areas for canvassing and administering the census. The collection areas and their hierarchy used in the Census 2000 was different from those used in the 1990 census. Census 2000 collection blocks were unique within collection state and county. The Census 2000 collection blocks generally followed visible features such as roads, rivers, and railroad tracks. Census 2000 collection blocks appear only in the TIGER/Line files; the U.S. Census Bureau did not tabulate data for collection blocks. 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. Refer to the section on Crews-of-Vessels later in this chapter for more information. The Census 2000 collection blocks are numbered uniquely within county (or statistically equivalent entity) with a four- or five-digit number. Census 2000 collection blocks are unique within collection state and county; they do not nest within census tract. To control the Census 2000 collection block numbers during the collection process, the U.S. Census Bureau retained the original collection state and county codes even if the state and county changed after the original Census 2000 collection blocks were delineated. The collection state and county codes reflect the boundaries of those areas at the time of collection block numbering. To uniquely identify Census 2000 collection blocks, users must use the collection state and county code fields together with the collection block number and suffix fields. The U.S. Census Bureau assigned collection block suffixes to some Census 2000 collection blocks split by road features added to Census TIGER(R) after the assignment of the Census 2000 collection block numbers. The U.S. Census Bureau also assigned collection block suffixes to reflect updated American Indian reservation, American Indian trust land, and military installation boundaries. There is no relationship between the Census 2000 block numbers and the 1990 tabulation block numbers. Nor is there a relationship or correlation between the Census 2000 tabulation block numbers and collection block numbers. 1990 Census Block Numbers 1990 census blocks were numbered uniquely within each 1990 state/county/census tract or block numbering area (BNA). A 1990 census block was identified by a 3-character basic block number and an optional 1-character alphabetic suffix. Many 1990 census blocks did not have suffixes. 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. The U.S. Census Bureau assigned collection water block numbers within a county beginning with 9999 or 99999 and preceding in descending order. For example, the collection water block numbers in a county would be 9999, 9998, 9997, and so forth. In some block groups, the numbering of land blocks might use enough of the available tabulation block numbers to reach beyond the 900 range within the block group. For this reason, and 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. Census Block Number Record Locations Record Type Field Name Description 1 BLOCKL Census Block Number, 2000 Left 1 BLOCKR Census Block Number, 2000 Right 3 BLOCK90L Census Block Number, 1990 Left 3 BLOCK90R Census Block Number, 1990 Right A BLOCK90 Census Block Number, 1990 S BLOCK Census Block Number, 2000 S BLOCKCOL Census 2000 Collection Block Number S BLKSUFCOL Census 2000 Collection Block Number Suffix Census Block Codes Census 2000 Tabulation Blocks Block Group Number 0 to 9-First character 000 to 999-Second, third, and forth characters Census 2000 Collection Blocks 1001 to 9999 or 10001 to 99999 Census 2000 Collection Block Suffixes A to Z-Codes for Census 2000 collection blocks with a suffix 1990 Land Blocks Block Group Number 1 to 9-First character 01 to 97-Second and third characters Block numbers ending in 98 were not used 1990 Water Blocks Block Group Number 0 to 9-First character 99-Second and third characters 1990 Tabulation Block Suffixes A to Y-Codes for land blocks with a suffix A to Y, a to y-Codes for water blocks with a suffix Z-Code for blocks assigned for the enumeration of crews-of-vessels All polygons have a non-blank 4-digit Census 2000 block number. The left- and right-side complete chain block numbers are not blank except where they are located along the outside edge of the county. The TIGER/Line files do not contain geographic codes for the area outside of the county file. The TIGER/Line files identify boundary complete chains by placing a 1 in the single-side segment field in Record Type 1. Census Tracts Census tracts are small, relatively permanent statistical subdivisions of a county (or statistical equivalent of a county), and are defined by local participants as part of the U.S. Census Bureau's Participant Statistical Areas Program. The U.S. Census Bureau delineated the census tracts in situations where no local participant existed or where local or tribal governments declined to participate. The primary purpose of census tracts is to provide a stable set of geographic units for the presentation of decennial census data. Census 2000 is the first decennial census for which the entire United States has census tracts. In 1990 some counties had census tracts and others had block numbering areas (BNAs). In preparation for Census 2000, all BNAs were replaced by census tracts. Block groups and census blocks are uniquely numbered within census tract (except for Census 2000 collection blocks which were uniquely numbered within county). Census tracts generally have a population size between 1,500 and 8,000 people, with an optimum size of 4,000 people. When first delineated, census tracts are designed to be homogeneous with respect to population characteristics, economic status, and living conditions. The spatial size of census tracts varies widely depending on the density of settlement. Census tract boundaries are delineated with the intention of being maintained over a long time so that statistical comparisons can be made from census to census. However, physical changes in street patterns caused by highway construction, new development, and so forth, may require boundary revisions. In addition, census tracts occasionally are split due to population growth, or combined as a result of substantial population decline. Census Tract Numbering Census tract numbers have a 4-digit basic number and may have an optional 2-digit suffix; for example, 1457.02. Census tract numbers range from 0001 to 9999 and are unique within a county or equivalent area. The U.S. Census Bureau reserves the census tract numbering range of 9400 to 9499 for use by American Indian area participants in situations where an American Indian entity crosses county or state lines. See the section on Census Tracts in American Indian Areas below for further information. The U.S. Census Bureau assigns a default census tract number of 0000 to some coastal and Great Lakes water and territorial sea rather than extend the census tract boundary into the Great Lakes or out to the three-mile limit. By closing off some census tracts along the shoreline or just offshore and assigning the default census tract to the offshore water areas, the U.S. Census Bureau provides complete census tract coverage of water areas in territorial seas and the Great Lakes. Census tract suffixes may range from .01 to .98. For Census 2000, the U.S. Census Bureau is not identifying separate crews-of-vessels census tracts; the crews-of-vessels population will be part of the Census 2000 census tract identified as associated with the homeport of the vessel. See the section on Crews-of-Vessels later in this chapter for further information. The U.S. Census Bureau uses suffixes to help identify census tract changes for comparison purposes. Local participants have an opportunity to review the existing census tracts before each census. If local participants split a census tract, the split parts usually retain the basic number, but receive different suffixes. In a few counties, local participants request major changes to, and renumber, the census tracts. Changes to individual census tract boundaries usually do not result in census tract numbering changes. In printed reports and on mapping products, the U.S. Census Bureau uses a decimal point (.) to separate the basic number from the suffix. However, in the TIGER/Line files and Summary File (SF) data products, the decimal point is implied. The basic number and the suffix appear together in a single 6-character field in Record Types 1, 3, A, and S. A basic number smaller than 1000 will contain leading zeros (for example, 002502). Leading zeros are shown on machine-readable products, but are not shown in printed reports or on census maps. The TIGER/Line files use the right-most two characters in the census tract field for the suffix. Where a census tract suffix does not exist, the suffix is zero filled in machine-readable products, but blank in printed reports, on census maps, and in the 1998 and earlier TIGER/Line files. Beginning with the 1999 TIGER/Line files, zeros will appear in the right-most two characters in the census tract field where a census tract suffix does not exist. Suffixes smaller than 10 have a leading zero. For example, census tract 0077.01 is shown as 007701 in the TIGER/Line files. Census Tract "Name" The Census 2000 TIGER/Line files contain the census tract numbers formatted to display as they appear on U.S. Census Bureau printed reports and on mapping products. That is, in the census tract "name" the leading and trailing zeros in the census tract number are omitted and the decimal point appears in those census tract numbers with a suffix. For example, census tract 000302 has a census tract "name" of 3.02 and the "name" for census tract 020800 is 208. Data users will find the census tract numbers formatted to display as a "name" on Record Type C. The census tract number appears in the Census Voting District Code/Census Tract Code field (field name VTDTRACT) and the census tract "name" appears in the Name of Geographic Area field. To distinguish between the voting district codes and census tract codes in the VTDTRACT field, users should use the Entity Type Code field on Record Type C. Census tract numbers have an entity type code of "T." Boundaries and Boundary Changes Census tract boundaries generally follow visible and identifiable features. Census tract boundaries may follow legal boundaries, such as minor civil division (MCD) or incorporated place boundaries, in some states and situations to allow for census tract-to- governmental unit relationships where the governmental boundaries tend to remain unchanged between censuses. State and county boundaries are always census tract boundaries in the standard census geographic hierarchy. Under the Census 2000 American Indian/Alaska Native area/Hawaiian home land census geographic hierarchy, tribal census tracts are defined within American Indian entities and can cross state and county boundaries. In a few rare instances, a census tract may consist of discontiguous areas. These discontiguous areas may occur where the census tracts are coextensive with all or parts of legal entities that are themselves discontiguous. Census Tracts in American Indian Areas The U.S. Census Bureau has reserved the census tract numbering range of 9400 to 9499 for use by American Indian area participants in situations where an American Indian entity crosses county or state boundaries. Under the Census 2000 American Indian/Alaska Native area/Hawaiian home land census geographic hierarchy, the U.S. Census Bureau will tabulate census tract data within federally recognized American Indian reservations and off-reservation trust lands ignoring state and county boundaries. These are commonly referred to as tribal census tracts. Relationship to Other Geographic Entities Within the standard census geographic hierarchy, census tracts never cross state or county 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 home land census geographic hierarchy, tribal census tracts are defined within American Indian entities and cross state and county boundaries. 1990 Census Tracts and Block Numbering Areas (BNAs) BNAs were statistical areas delineated for the 1990 census by state agencies or the U.S. Census Bureau for counties without census tracts. The delineation of 1990 BNAs followed the same basic criteria as those for 1990 census tracts. Because BNAs appear more often in less populated counties, they may have fewer people than census tracts. The 1990 census tracts and BNAs represent the same level of geography and share the same field in the TIGER/Line files. 1990 census tracts or BNAs entirely cover a county. A county contained either 1990 census tracts or BNAs, but not a combination of both. For the 1990 census, the U.S. Census Bureau used the .99 suffix for census tracts/BNAs that contained only "crews-of-vessels" population. For Census 2000, the U.S. Census Bureau is not identifying separate crews-of-vessels census tracts; the crews-of-vessels population will be part of the Census 2000 census tract identified as associated with the homeport of the vessel. See the section on Crews-of-Vessels later in this chapter for further information. Census Tract Code Record Locations Record Type Field Name Description 1 TRACTL Census Tract Code, 2000 Left 1 TRACTR Census Tract Code, 2000 Right 3 TRACT90L Census Tract/BNA Code, 1990 Left 3 TRACT90R Census Tract/BNA Code, 1990 Right A TRACT90 Census Tract/BNA Code, 1990 C ENTITY Entity Type Code C VTDTRACT Census Voting District Code/Census Tract Code C NAME Name of Geographic Area S TRACT Census Tract Code, 2000 Census Tract Codes Census 2000 Census Tract Codes 0001 to 9989-Basic number range for census tracts 9400 to 9499-Basic number range for census tracts delineated within or to encompass American Indian entities 0000-Default basic number for census tracts 01 to 98-Suffix codes for census tracts 00-Suffix code for census tracts without a suffix 1990 Census Tract/BNA Codes 0001 to 9499-Basic number range for 1990 census tracts 9500 to 9989-Basic number range for 1990 BNAs 0000-Default basic number for 1990 census tracts/BNAs 01 to 98-Suffix codes for 1990 census tracts 85 to 98-Suffix codes for 1990 BNAs blank-Suffix code for 1990 census tracts and BNAs without a suffix 99-Suffix code for 1990 crews-of-vessels census tracts/BNAs All polygons have a non-blank census tract basic number. The left- and right-side complete chain census tract numbers are not blank except where they are located along the outside edge of the county boundary. The TIGER/Line files do not contain geographic codes for the area outside of the county file. The TIGER/Line files identify the boundary complete chains by placing a 1 in the single-side segment field in Record Type 1. Congressional Districts Congressional districts are the 435 areas from which people are elected to the U.S. House of Representatives. After the apportionment of congressional seats among the states, based on census population counts, each state is responsible for establishing congressional districts for the purpose of electing representatives. Each congressional district is to be as equal in population to all other congressional districts in a state as practicable. The congressional districts in effect at the time of Census 2000 are those of the 106th Congress, whose session began in January 1999. The congressional districts for the 103rd Congress (January 1993 to 1995) were the first to reflect redistricting based on the 1990 census. The 103rd Congressional Districts will remain in effect through Census 2000, except where a state initiative or a court-ordered redistricting required a change. Six states redistricted for the 104th Congress (Georgia, Louisiana, Maine, Minnesota, South Carolina, and Virginia), five states redistricted for the 105th Congress (Florida, Georgia, Kentucky, Louisiana, and Texas), and three states (New York, North Carolina, and Virginia) redistricted for the 106th Congress. In North Carolina the "1998 Congressional Plan A" was used for the 1998 congressional elections. It was created in response to a court ruling which held the 1997 plan, "97 House/Senate Plan A," unconstitutional. The Supreme Court has since reversed that lower court ruling and was used for the 2000 North Carolina congressional elections. The 106th Congressional Districts appearing in the Census 2000 TIGER/Line files for North Carolina are the "97 House/Senate Plan A" Congressional Districts. The 108th Congress will be the first to reflect reapportionment and redistricting based on Census 2000 data. Congressional districts are identified by a 2-character numeric FIPS code. The Census 2000 TIGER/Line files contain fields for the current (106th ), the 106th, and the 108th Congressional Districts. Congressional districts are numbered uniquely within state. The field for the 108th Congressional Districts is blank. The current congressional district field always has a value other than blank for all polygons. Congressional District Record Locations Record Type Field Name Description A CD106 Congressional District Code, 106th A CD108 Congressional District Code, 108th S CDCU Congressional District Code, Current (106th) Congressional District Codes-106th Congress 01 to 52-Congressional district codes 00-At large (single district for state) 98-Nonvoting delegate 99-Area with no representative in Congress Counties and Statistically Equivalent Entities The primary legal divisions of most states are termed "counties." In Louisiana, these divisions are know as "parishes." In Alaska, which has no counties, the statistically equivalent entities are the organized "boroughs," "city and boroughs," "municipality," and "census areas;" the latter are delineated cooperatively for statistical purposes by the State of Alaska and the U.S. Census Bureau. In four states (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are independent of any county organization and thus constitute primary divisions of their states. These incorporated places are known as "independent cities" and are treated as statistically equivalent entities for purposes of data presentation. The District of Columbia has no primary divisions, and the entire area is considered a statistically equivalent entity for purposes of data presentation. The U.S. Census Bureau treats the following entities as statistical equivalents of counties for purposes of data presentation: municipios in Puerto Rico; Islands in the U.S. Virgin Islands; and a variety of entities in the Pacific Island Areas. The TIGER/Line files contain several 3-character numeric fields identifying the FIPS county code for Census 2000 and the 1990 census. Each individual TIGER/Line file contains state and county code fields to uniquely identify its records. See Appendix A for a list of FIPS codes for county and statistically equivalent entities. Since the 1990 Census, there were several changes to the universe of county or statistically equivalent entities. In Alaska the Skagway-Yakutat-Angoon Census Area became Skagway-Hoonah-Angoon Census Area and Yakutat City and Borough. Also in Alaska, Denali Borough was created from parts of Yukon-Koyukuk Census Area and Southeast Fairbanks Census Area. Dade County, Florida officially changed its legal name to Miami-Dade County, Florida. The portion of Yellowstone National Park in Montana that the U.S. Census Bureau had been showing as a statistical equivalent of a county in the 1990 census legally was annexed by referendum to Gallatin and Park Counties, Montana. The City of South Boston, Virginia no longer is an independent city and is now part of Halifax County, Virginia. The Census 2000 TIGER/Line files are based on the boundaries of the counties or statistical equivalent entities as reported to the U.S. Census Bureau to be legally in effect on January 1, 2000. Census 2000 Collection County Census 2000 uses a set of collection geographic areas for canvassing and administering the census. Because Census 2000 collection blocks are numbered uniquely within collection state and county, the U.S. Census Bureau retains the original collection state and county codes even if the state and county changed after the original Census 2000 collection blocks are delineated. See the Census Block section in this chapter for information on collection blocks. County and Statistically Equivalent Entity Code Record Locations Record Type Field Name Description 1 COUNTYL FIPS County Code, 2000 Left 1 COUNTYR FIPS County Code, 2000 Right 3 COUNTY90L FIPS County Code, 1990 Left 3 COUNTY90R FIPS County Code, 1990 Right A COUNTY90 FIPS County Code, 1990 C COUNTY FIPS County Code C ENTITY Entity Type Code C NAME Name of Geographic Area S COUNTY FIPS County Code, 2000 S COUNTYCOL Census 2000 Collection County FIPS Code County Subdivisions County subdivisions are the primary divisions of counties and their statistical equivalents for the reporting of decennial census data. They include census county divisions, census subareas, minor civil divisions, and unorganized territories. The TIGER/Line files contain a 5-character numeric FIPS code field for county subdivisions. They use a single field to identify the two functional types (legal and statistical) of county subdivisions. Record Type C contains all valid codes and entity names. Legal Entities Minor Civil Divisions (MCDs) MCDs are the primary governmental or administrative divisions of a county in many states. MCDs represent many different kinds of legal entities with a wide variety of governmental and/or administrative functions. MCDs are variously designated as American Indian reservations, assessment districts, boroughs, election districts, gores, grants. locations, magisterial districts, parish governing authority districts, plantations, precincts, purchases, road districts, supervisor's districts, towns, and townships. The U.S. Census Bureau recognizes MCDs in 28 states, Puerto Rico, and the Island Areas. The District of Columbia has no primary divisions, and the District of Columbia is considered equivalent to an MCD for statistical purposes. In some states, all or some incorporated places are not part of any MCD. These places also serve as primary legal subdivisions and have a unique FIPS MCD code that is the same as the FIPS place code. The TIGER/Line files will show the same FIPS 55 code in the county subdivision field and the place field. In other states, incorporated places are part of the MCDs in which they are located, or the pattern is mixed-some incorporated places are independent of MCDs and others are included within one or more MCDs. The MCDs in 12 states (Connecticut, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and Wisconsin) also serve as general -purpose local governments that generally can perform the same governmental functions as incorporated places. The U.S. Census Bureau presents data for these MCDs in all data products in which it provides data for places. In New York and Maine, American Indian reservations (AIRs) exist outside the jurisdiction of any town (MCD) and thus also serve as the statistical equivalent of MCDs for purposes of data presentation. Statistical Entities Census County Divisions (CCDs) CCDs are areas delineated by the U.S. Census Bureau, in cooperation with state officials and local officials for statistical purposes. CCDs have no legal function and are not governmental units. CCD boundaries usually follow visible features and in most cases, coincide with census tract boundaries. The name of each CCD is based on a place, county, or well-known local name that identifies its location. CCDs exist where: 1) There are no legally established minor civil divisions (MCDs). 2) The legally established MCDs do not have governmental or administrative purposes. 3) The boundaries of the MCDs change frequently. 4) The MCDs are not generally known to the public. CCDs have been established for the following 21 states: Alabama Hawaii Oregon Arizona Idaho South Carolina California Kentucky Tennessee Colorado Montana Texas Delaware Nevada Utah Florida New Mexico Washington Georgia Oklahoma Wyoming Census Subareas Census subareas are statistical subdivisions of boroughs, city and boroughs, municipalities, and census areas, the statistical equivalent entities for counties in Alaska. The state of Alaska and the U.S. Census Bureau cooperatively delineate the census subareas to serve as the statistical equivalents of MCDs. Census subareas were first used in the 1980 census. Unorganized Territories (UTs) The U.S. Census Bureau defines unorganized territories in 10 minor civil division (MCD) states where portions of counties are not included in any legally established MCD or incorporated place. The U.S. Census Bureau recognizes such separate pieces of territory as one or more separate county subdivisions for census purposes. It assigns each unorganized territory a descriptive name, followed by the designation "unorganized territory" and a county subdivision code. Unorganized territories were first reported in the 1960 census. The following states have unorganized territories: Arkansas Minnesota Indiana North Carolina Iowa North Dakota Louisiana Ohio Maine South Dakota County Subdivision Code Record Locations Record Type Field Name Description 1 COUSUBL FIPS 55 Code (County Subdivision), 2000 Left 1 COUSUBR FIPS 55 Code (County Subdivision), 2000 Right 3 COUSUB90L FIPS 55 Code (County Subdivision), 1990 Left 3 COUSUB90R FIPS 55 Code (County Subdivision), 1990 Right A COUSUB90 FIPS 55 Code (County Subdivision), 1990 C FIPS FIPS PUB 55-3 Code C ENTITY Entity Type Code C NAME Name of Geographic Area S COUSUB FIPS 55 Code (County Subdivision), 2000 The U.S. Census Bureau assigns a default county subdivision code of 00000 in some coastal and Great Lakes water where county subdivisions do not extend into the Great Lakes or out to the three-mile limit. Crews-of-Vessels Crews-of-vessels refers to the population on military (including Coast Guard) and merchant ships; they do not include the inhabitants of houseboats or marinas. The 1990 census population tables showed the vessels' population in a unique 1990 census tract and block. A 1990 crews- of-vessels census tract appeared on 1990 census maps as an anchor symbol with the census tract number, rather than as a delimited area. The location of the anchor symbol was arbitrary and reflected neither the location of the vessel(s) at the time of the 1990 census, nor the location of the 1990 crews- of-vessels census tract as it appeared in the TIGER/Line files. 1990 crews-of-vessels census tract numbers used the same basic census tract number as the nearby land census tract with which the vessel was associated, plus a suffix of 99, shown in decimal notation. 1990 Crews-of- vessels block numbers used the same basic 1990 block number as the associated land block in that 1990 census tract/BNA, plus a block suffix of Z; for example, block 901Z in 1990 census tract 1234.99. For Census 2000, the U.S. Census Bureau is not delineating separate crews- of-vessels census tracts or blocks. Instead it is assigning the crews-of-vessels population to the land block identified as being associated with the homeport of the vessel. A point landmark, with the census feature class code (CFCC) of D25, appears in the TIGER/Line files indicating within which Census 2000 tabulation block(s) the crews-of-vessels population is assigned. Metropolitan Areas (MAs) Metropolitan areas (MAs) are designated and defined by the U.S. Office of Management and Budget (OMB), following a set of official standards that are published in a Federal Register Notice. These standards were developed by the interagency Metropolitan Area Standards Review Committee, with the aim of producing definitions that are as consistent as possible for all MAs nationwide. The general concept of an MA is one of a large population nucleus, together with adjacent communities that have a high degree of economic and social integration with that nucleus. Some MAs are defined around two or more nuclei. Each MA must contain either a place with a minimum population of 50,000 or a U.S. Census Bureau defined urbanized area and a total MA population of at least 100,000 (75,000 in New England). An MA contains one or more central counties and may include one or more outlying counties that have close economic and social relationships with the central county. An outlying county must have a specified level of commuting to the central counties and also must meet certain standards regarding metropolitan character, such as population density, urban population, and population growth. In New England, MAs consist of cities and towns rather than whole counties. The territory, population, and housing units in MAs are referred to as "metropolitan." The metropolitan category is subdivided into "inside central city" and "outside central city." The territory, population, and housing units located outside MAs are referred to as "nonmetropolitan." The metropolitan and nonmetropolitan classification cuts across the other hierarchies; for example, there is generally both urban and rural territory within both metropolitan and nonmetropolitan areas. There are three types of metropolitan areas. If a metropolitan area has a total population of less than 1,000,000, the area is designated a Metropolitan Statistical Area (MSA). Metropolitan areas with a population of 1,000,000 or greater qualify for designation as a Consolidated Metropolitan Statistical Area (CMSA) that is composed of smaller Primary Metropolitan Statistical Areas (PMSAs). This designation is not automatic; the OMB solicits local opinion to designate CMSAs and their component PMSAs. The TIGER/Line files contain two different 4-character numeric fields to identify the FIPS code for each metropolitan area and to differentiate CMSAs and MSAs from PMSAs. The FIPS codes are from FIPS PUB 8. If the metropolitan area is a CMSA then a value exists in the MSACMSA field identifying the CMSA and the value in the PMSA field identifies the PMSA. A blank PMSA field indicates the code in the MSACMSA field is for the MSA. Record Type C uses a single metropolitan area field to identify CMSAs, MSAs, and PMSAs. The Legal/Statistical Area Description code identifies the type of metropolitan area. Metropolitan Area Central Cities In each metropolitan statistical area (MSA) and consolidated metropolitan statistical area (CMSA), the largest place and, in some cases, additional places are designated as "central cities" under the official standards. A few primary metropolitan statistical areas (PMSAs) do not have central cities. The largest central city and, in some cases, up to two additional central cities are included in the title of the MA; there also are central cities that are not included in an MA title. An MA central city does not include any part of that place that extends outside the MA boundary. Consolidated Metropolitan Statistical Areas (CMSAs) and Primary Metropolitan Statistical Areas (PMSAs) If an area that qualifies as an MA has more than one million people, primary metropolitan statistical areas (PMSAs) may be defined within it. PMSAs consist of a county or cluster of counties (cities and towns in New England) that demonstrates very strong internal economic and social links, in addition to close ties to other portions of the larger area. When PMSAs are established, the larger MA of which they are component parts is designated a consolidated metropolitan statistical area (CMSA). CMSAs and PMSAs are established only where local governments favor such a designation for a large MA. Metropolitan Statistical Areas (MSAs) Metropolitan statistical areas (MSAs) are MAs that are not closely associated with other MAs. These areas typically are surrounded by nonmetropolitan counties (county subdivisions in New England). New England County Metropolitan Areas (NECMAs) New England county metropolitan areas (NECMAs) are defined as a county-based alternative to the city and town based New England MSAs and CMSAs. The NECMA defined for an MSA or CMSA includes: The county containing the first-named city in that MSA/CMSA title (this county may include the first-named cities of other MSAs/CMSAs as well. Each additional county having at least half its population in the MSAs/CMSAs whose first-named cities are in the previously identified county. NECMAs are not identified for individual PMSAs. Only the CMSAs, MSAs, and PMSAs appear in the TIGER/Line files. The U.S. Census Bureau does not include NECMAs in the TIGER/Line files. Metropolitan Area Code Record Locations Record Type Field Name Description C MA Metropolitan Area Code C ENTITY Entity Type Code C NAME Name of Geographic Area S MSACMSA FIPS Consolidated Metropolitan Statistical Area/ Metropolitan Statistical Area Code, 2000 S PMSA FIPS Primary Metropolitan Statistical Area Code, 2000 Metropolitan Area Codes Metropolitan areas are identified using the 4- character numeric FIPS codes. Record Type C in the TIGER/Line files contains all the valid Census 2000 codes and entity names for CMSAs, MSAs, and PMSAs. Places The TIGER/Line files use a single field to identify places that are legal entities, and places that are statistical entities. The FIPS place code uniquely identifies a place within a state. If place names are duplicated within a state and they represent distinctly different areas, a separate code is assigned to each place name alphabetically by primary county in which each place is located, or if both places are in the same county, alphabetically by their legal descriptions (for example, "city" before "village"). Legal Entities Consolidated Cities A consolidated government is a unit of local government for which the functions of an incorporated place and its county or minor civil division (MCD) have merged. The legal aspects of this action may result in both the primary incorporated place and the county or MCD continuing to exist as legal entities, even though the county or MCD performs few or no governmental functions and has few or no elected officials. Where this occurs, and where one or more other incorporated places in the county or MCD continue to function as separate governments, even though they have been included in the consolidated government, the primary incorporated place is referred to as a "consolidated city." The U.S. Census Bureau classifies the separately incorporated places within the consolidated city as place entities and creates a separate place (balance) record for the portion of the consolidated city not within any other place. Refer to the section on Consolidated City (Balance) Portions below for additional information. Consolidated cities are represented in the TIGER/Line files by a 5-character numeric FIPS code. Record Type C has the complete list of valid codes and entity names. Incorporated Places Incorporated places are those reported to the U.S. Census Bureau as legally in existence on January 1, 2000, under the laws of their respective states. An incorporated place is established to provide governmental functions for a concentration of people as opposed to a minor civil division, which generally is created to provide services or administer an area without regard, necessarily, to population. Places may extend across county and county subdivision boundaries. An incorporated place can be a city, city and borough, borough, municipality, town, village, or rarely, undesignated. But, for census purposes, incorporated places exclude: The boroughs in Alaska (treated as statistical equivalents of counties) Towns in the New England States, New York, and Wisconsin (treated as MCDs) The boroughs in New York (treated as MCDs) The balance portions of consolidated cities (statistical equivalents of incorporated places) The incorporated places known as "independent cities" in Maryland, Missouri, Nevada, and Virginia (treated as statistical equivalents of counties) Statistical Entities Census Designated Places (CDPs) CDPs are delineated for the decennial census as the statistical counterparts of incorporated places. CDPs are delineated to provide data for settled concentrations of population that are identifiable by name but are not legally incorporated under the laws of the state in which they are located. The boundaries usually are defined in cooperation with local or tribal officials. These boundaries, which usually coincide with visible features or the boundary of an adjacent incorporated place or a other legal entity boundary, have no legal status, nor do these places have officials elected to serve traditional municipal functions. CDP boundaries may change from one decennial census to the next with changes in the settlement pattern; a CDP with the same name as in an earlier census does not necessarily have the same boundary. There are no population size requirements for CDPs for Census 2000. For the 1990 and previous censuses, the U.S. Census Bureau required CDPs to qualify on the basis of various minimum population size criteria. Hawaii is the only state that has no incorporated places recognized by the U.S. Census Bureau. All places shown in the Census 2000 data products for Hawaii are CDPs. By agreement with the State of Hawaii, the U.S. Census Bureau does not show data separately for the city of Honolulu, which is coextensive with Honolulu County. In Puerto Rico, which also does not have incorporated places, the U.S. Census Bureau recognizes only CDPs. The CDPs in Puerto Rico are called comunidades or zonas urbanas. Guam and the Northern Mariana Islands also have only CDPs. Consolidated City (Balance) Portions Consolidated city (balance) portions refer to the areas of a consolidated city not included in another incorporated place. For example, Columbus city, GA, is a consolidated city that includes the separately incorporated municipality of Bibb City town. The area of the consolidated city that is not in Bibb City town is assigned to Columbus city (balance). The name always includes the "(balance)" identifier. Dependent and Independent Places Depending on the state, incorporated places are either dependent within, or independent of, county subdivisions, or there is a mixture of dependent and independent places in the state. Dependent places are part of the county subdivision; the county subdivision code of the place is the same as that of the underlying county subdivision(s), but is different from the FIPS place code. Independent places are separate from the adjoining county subdivisions and have their own county subdivision code (or codes if the place lies in multiple counties). These places also serve as primary county subdivisions. The TIGER/Line files will show the same FIPS 55 code in the FIPS county subdivision code field and the FIPS place code field for independent places. The only exception is if the place is independent of the MCDs in a state in which the FIPS MCD codes are in the 90000 range. Then, the FIPS MCD and FIPS place codes will differ. CDPs and balance portions of consolidated cities (Class C8) always are dependent within county subdivisions. Corporate Corridors and Offset Corporate Boundaries A corporate corridor is a narrow, linear part of an incorporated place (or in a very few instances, another legal entity). The corporate corridor includes the street and/or right-of-way, or a portion of the street and/or right-of-way within the incorporated place. It excludes from the incorporated place those structures such as houses, apartments, or businesses, that front along the street or road. A corporate limit offset boundary exists where the incorporated place lies on only one side of the street, and may include all or part of the street and/or the right-of-way. It does not include the houses or land that adjoin the side of the street with the corporate limit offset boundary. It is possible to have two or more corporate limit offset boundaries in the same street or right-of- way. Corporate limit offset boundaries use the same map symbology as non- offset boundaries.. To facilitate address coding, the street name and address ranges are generally duplicated on complete chains with a CFCC of F11 (offset boundary of a legal entity) or F12 (corridor boundary of a legal entity). The duplicate street names for the F11 and F12 features are on Record Type 5 and the duplicate address ranges are on Record Type 6. However, Record Type 1 will not indicate that the street or right-of-way lies within a corporate corridor or offset boundary, or that the address ranges lie outside, and are encoded on either side, of the corporate corridor or offset boundary. When data users find duplicate address ranges where one of the duplicates is on a complete chain with a CFCC of F11 or F12, they should use this address range for address geocoding rather than the range on the street feature that has a CFCC beginning with A. Likewise, use the street name and address ranges on the related street feature (CFCC beginning with A) for mapping or vehicle routing. Incorporated Place/CDP Code Record Locations Record Type Field Name Description 1 PLACEL FIPS 55 Code (Place/CDP), 2000 Left 1 PLACER FIPS 55 Code (Place/CDP), 2000 Right 3 PLACE90L FIPS 55 Code (Place/CDP), 1990 Left 3 PLACE90R FIPS 55 Code (Place/CDP), 1990 Right A PLACE90 FIPS 55 Code (Place/CDP), 1990 C FIPS FIPS PUB 55-3 Code C ENTITY Entity Type Code C NAME Name of Geographic Area S CONCIT FIPS 55 Code (Consolidated City), 2000 S PLACE FIPS 55 Code (Incorporated Place/CDP), 2000 Legally incorporated places and CDPs are mutually exclusive and are identified in the same TIGER/Line field. Public Use Microdata Areas (PUMAs) Public Use Microdata Areas (PUMAs) are areas with a 1990 decennial census population of 100,000 or more people for which the U.S. Census Bureau provided specially selected extracts of raw data from a small sample of long- form census records that are screened to protect confidentiality. These extracts are referred to as public use microdata sample (PUMS) files. Data users used these 1990 files to create their own statistical tabulations and data summaries. The Census 2000 TIGER/Line files contain a Public Use Microdata Area File, 1990 field containing the PUMA codes from the 1990 1% sample. The U.S. Census Bureau inserted the 1990 PUMS 1% sample codes into the Census TIGER data base, but has not reviewed or verified that the PUMA codes as they appear in the Census 2000 TIGER/Line files accurately reflect the boundaries or codes of the 1990 PUMS 1% sample. The U.S. Census Bureau recommends that data users do not use the PUMAs appearing in the Census 2000 TIGER/Line files as they may not exactly represent the 1990 PUMAs. The codes contained in the PUMA1 field are for programmatic purposes only. Public Use Microdata Area Code Record Locations Record Type Field Name Description A PUMA1 Public Use Microdata Area File, 1990 School Districts School districts are geographic entities within which state, county, tribal, or local officials provide public educational services for the area's residents. The U.S. Census Bureau obtains the boundaries and names for school districts from state officials. The Census 2000 TIGER/Line files contain school district information from the 1999-2000 school year. The Census 2000 TIGER/Line files identify three levels of school districts representing different grade ranges of the school-age population (elementary and secondary) and a unified category to identify those school districts that represent all grade levels. The elementary and secondary levels of a school district can overlap each other because they represent different segments of the school-age population; for example, a secondary school district could cover parts of several elementary school districts. The TIGER/Line files use separate fields to accommodate for the overlap and may not contain a code for all grade levels. The TIGER/Line files contain a unified school district code for those school districts where all grade levels are represented in a single district. The elementary and secondary school district code fields are blank if there is a unified school district code. An exception exists for the State of Hawaii and the five boroughs of New York city where the National School District Program requested that the U.S. Census Bureau include the School Complex Areas in Hawaii and the Community School Districts in New York city. In Massachusetts and Tennessee some unified school districts also serve as secondary school districts in areas where there are elementary school districts. In these situations, the U.S. Census Bureau could not use the same school district code to identify school districts serving different grade ranges and has assigned two separate codes; a unified school district code and a separate "false" secondary school district code. Data users can identify the "false" school districts by looking for "-false" as part of the school district name appearing in Record Type C. A few additional exceptions occur where the Department of Defense operates elementary schools within a unified school district. The TIGER/Line files store the school district codes in a set of three, 5- character fields. All codes consist of numeric characters. The value, 99999, is a pseudo-school district code assigned to non-water blocks for which the National School District Program does not report a school district. Some large water areas have a pseudo-school district code of 99998. School District Code Record Locations Record Type Field Name Description A SDELM School District Code, Elementary School A SDSEC School District Code, Secondary School A SDUNI School District Code, Unified District C ENTITY Entity Type Code C SD School District Code C NAME Name of Geographic Area States and Statistically Equivalent Entities States are the primary governmental divisions of the United States. In addition to the 50 States, the U.S. Census Bureau treats the District of Columbia, Puerto Rico, the U.S. Virgin Islands, and the Pacific Island Areas (American Samoa, Guam, and the Northern Mariana Islands) as the statistical equivalent of a state for the purpose of data presentation. TIGER/Line files are produced for the 50 States, the District of Columbia, the U.S. Virgin Islands, Puerto Rico, and the Pacific Island Areas. See Appendix A for a list of the FIPS state codes. Census 2000 Collection State Census 2000 uses a set of collection geographic areas for canvassing and administering the census. Because Census 2000 collection blocks are numbered uniquely within collection state and county, the U.S. Census Bureau retained the original collection state and county codes even if the state and county changed after the original Census 2000 collection blocks were delineated. See the Census Block section in this chapter for information on collection blocks. State Code Record Locations Record Type Field Name Description 1 STATEL FIPS State Code, 2000 Left 1 STATER FIPS State Code, 2000 Right 3 STATE90L FIPS State Code, 1990 Left 3 STATE90R FIPS State Code, 1990 Right A STATE90 FIPS State Code, 1990 C STATE FIPS State Code C ENTITY Entity Type Code C NAME Name of Geographic Area S STATE FIPS State Code, 2000 S STATECOL Census 2000 Collection State FIPS Code State Legislative Districts (SLDs) State legislative districts (SLDs) are the areas from which members are elected to state legislatures. States participating in the Census 2000 Redistricting Data Program as part of Public Law 94-171 (1975) may provide the U.S. Census Bureau with boundaries and codes for their SLDs. The U.S. Census Bureau is reporting data for SLDs for the first time for Census 2000. The SLDs embody the upper (senate) and lower (house) chambers of the state legislature. (Nebraska has a unicameral legislature that the U.S. Census Bureau treats as an upper-chamber legislative area for purposes of data presentation. New Hampshire only submitted SLDs for the upper chamber. Therefore, there are no data by lower chamber for these two states.) A unique 1- to 3-character census code, identified by state participants, is assigned to SLD within state. It is possible to have SLDs that cover only part of a state. In such instances, any areas for which SLDs are not defined are coded "ZZZ" and treated as a single SLD for purposes of data presentation. The following states did not participate in Phase 2 (the Voting District Project) of the Census 2000 Redistricting Data Program and no SLDs appear for these states: California Florida Kentucky Montana Of the participating states (or statistically equivalent entities), the following did not submit SLD boundaries or codes as part of Phase 2 (the Voting District Project) of the Census 2000 Redistricting Data Program, but submitted Voting Districts (VTDs) only: Arkansas Maine Texas District of Columbia Maryland Puerto Rico Hawaii Minnesota SLD Code Record Locations Record Type Field Name Description C FIPS FIPS PUB 55-3 Code C ENTITY Entity Type Code C NAME Name of Geographic Area SLD Code Record Locations (cont.) Record Type Field Name Description S SLDU State Legislative District Code (Upper Chamber), 2000 S SLDL State Legislative District Code (Lower Chamber), 2000 Subbarrios (Sub-Minor Civil Divisions or Sub-MCDs) Subbarrios are legally defined subdivisions of the minor civil division barrios- pueblo and barrios in Puerto Rico. The TIGER/Line files contain the 5-character FIPS 55 code field for Subbarrios. Subbarrio Code Record Locations Record Type Field Name Description 1 SUBMCDL FIPS 55 Code (Subbarrio), 2000 Left 1 SUBMCDR FIPS 55 Code (Subbarrio), 2000 Right C FIPS FIPS PUB 55-3 Code C ENTITY Entity Type Code C NAME Name of Geographic Area S SUBMCD FIPS 55 Code (Subbarrio), 2000 Traffic Analysis Zones (TAZs) Traffic analysis zones (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. For Census 2000 TAZs are defined within county. 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. The U.S. Census Bureau first provided data for TAZs in the 1980 census, when it identified them as "traffic zones." For the 1990 census, the TAZs were defined within Census Transportation Planning Package (CTPP) areas. TAZs were not shown in any 1990 Census TIGER extracts. The U.S. Census Bureau subsequently inserted the TAZs into the Census TIGER data base and began extracting them starting with the 1994 TIGER/Line files. The Census 2000 TAZ program was conducted on behalf of the Federal Highway Administration, Department of Transportation, which offered participation to the Metropolitan Planning Organizations (MPOs) and the Departments of Transportation (DOTs) in the 50 states and the District of Columbia. The following states did not have a participating MPO or State DOT for the Census 2000 TAZ Program: Delaware Hawaii Montana The following states did not submit TAZ boundaries or codes for all counties: Alabama Louisiana Oklahoma Alaska Maryland Oregon Arizona Massachusetts Pennsylvania Arkansas Minnesota Tennessee California Mississippi Texas Colorado Missouri Utah Florida Nevada Vermont Georgia New Jersey Virginia Idaho New Mexico Washington Illinois New York Wisconsin Indiana North Carolina Wyoming Iowa North Dakota Kansas Ohio TAZ Code Record Locations Record Type Field Name Description A TAZ Traffic Analysis Zone Code, 2000 Urban Growth Areas (UGAs) An urban growth area (UGA) is a legally defined entity in Oregon that the U.S. Census Bureau includes in the TIGER data base in agreement with the state. UGAs, which are defined around incorporated places, are used to regulate urban growth. UGA boundaries, which need not follow visible features, are delineated cooperatively by state and local officials and then confirmed in state law. UGAs, which are a pilot project, are a new geographic entity for Census 2000. Each UGA is identified by a 5-digit numeric census code, usually associated with the incorporated place name. UGA Code Record Locations Record Type Field Name Description C UAUGA Census Urban Area Code/Urban Growth Area Code C ENTITY Entity Type Code C NAME Name of Geographic Area S UGA Oregon Urban Growth Area, 2000 Urbanized Areas (UAs) A 1990 urbanized area (UA) consists of at least one central place and the adjacent densely settled surrounding territory that together have a minimum population of 50,000 people. The densely settled surrounding territory generally consists of an area with continuous residential development and a general overall population density of at least 1,000 people per square mile. The TIGER/Line files identify 1990 UAs with a 4-character numeric census code. All polygons that have a 1990 UA code (other than blank) will have a 1990 urban/rural (U/R) indicator equal to U. See the section, Urban/Rural Designation, in this chapter. UA Code Record Locations Record Type Field Name Description A UA90 Census Urbanized Area Code, 1990 C UAUGA Census Urban Area Code/Urban Growth Area Code C ENTITY Entity Type Code C NAME Name of Geographic Area Urban/Rural (U/R) Designation The U.S. Census Bureau defines urban for the 1990 census as consisting of all territory and population in urbanized areas (UAs) and in the urban portion of places with 2,500 or more people located outside of the UAs. For the 1990 census, the U.S. Census Bureau distinguished the urban and rural population within incorporated places whose boundaries contained large, sparsely populated, or even unpopulated area. These 1990 extended cities had to have either 25 percent of their land area, or at least 25 square miles, classified as sparsely settled. The sparsely settled area had to consist of at least one group of one or more contiguous census blocks. Each group must have consisted of at least five square miles in area and have an overall population density of less than 100 people per square mile. Polygons in the group of sparsely settled blocks have an indicator flag equal to R; the densely populated blocks will have an indicator flag equal to U. 1990 Incorporated places (based on 1990 census boundaries) with both urban- and rural-flagged polygons are extended cities. For the 1990 census, the U.S. Census Bureau defined 280 incorporated places as extended cities. Extended cities exist both inside and outside of UAs. The TIGER/Line files include a 1-character Urban/Rural Indicator: R- Rural, not urban U- Urban, in a UA or an urban place The U.S. Census Bureau assigns the U/R indicator to 1990 tabulation blocks, so all GT-polygons within a 1990 block have the same U/R indicator. All 1990 blocks that have a 1990 UA code (other than blank) will have a U/R indicator equal to U. 1990 blocks in places that qualify as urban places, but are not in a 1990 UA, do not have a UA code; they do have a U/R indicator equal to U. Rural areas are identified by the R indicator and will not have a UA code. U/R Indicator Record Locations Record Type Field Name Description A UR90 Urban/Rural Indicator, 1990 Voting Districts (VTDs) Voting district (VTD) is the generic name for geographic entities such as precincts, wards, and election districts established by state governments for the purpose of conducting elections. States participating in the Census 2000 Redistricting Data Program as part of Public Law 94-171 (1975) may provide the U.S. Census Bureau with boundaries, codes, and names for their VTDs. The U.S. Census Bureau first reported data for VTDs in the 1980 census. Each VTD is identified by a 1- to 6-character alphanumeric census code that is unique within county. The code "ZZZZZZ" identifies bodies of water for which no VTDs were identified. For a state or county that did not participate in Phase 2 (the Voting District Project) of the Census 2000 Redistricting Data Program, the codes fields are blank. Because the U.S. Census Bureau requires that VTDs follow boundaries of tabulation census blocks, participating states often show the boundaries of the VTDs they submit as conforming to tabulation census block boundaries. If requested by the participating state, the U.S. Census Bureau identifies the VTDs that represent an actual voting district with a Place Description Code of X. Where a participating state indicated that the VTD is a "pseudo" VTD, the Place Description Code is Z. Where a participating state did not indicate to the U.S. Census Bureau whether or not the VTD followed the actual boundaries of the VTD or is a pseudo-VTD the Place Description Code is blank. The following states did not participate in Phase 2 (the Voting District Project) of the Census 2000 Redistricting Data Program and no VTDs appear for these states: California Florida Kentucky Montana Of the participating states (or statistically equivalent entities), the following did not submit VTD boundaries or codes as part of Phase 2 (the Voting District Project) of the Census 2000 Redistricting Data Program, but submitted State Legislative Districts (SLDs) only: North Dakota Ohio Oregon Wisconsin The following state has partial coverage for Phase 2 (the Voting District Project) of the Census 2000 Redistricting Data Program: Arizona Did not submit VTDs in all counties VTD Code Record Locations Record Type Field Name Description C VTDTRACT Census Voting District Code/Census Tract Code C ENTITY Entity Type Code C NAME Name of Geographic Area C PLACEDC Place Description Code S VTD Census Voting District Code, 2000 ZIP Code Tabulation Areas (ZCTAs) ZIP Code Tabulation Areas (ZCTAs) are approximate area representations of United States Postal Service (USPS) ZIP Code service areas that the U.S. Census Bureau is creating for statistical purposes for Census 2000. The Census Bureau did not create ZCTAs for American Samoa, Guam, the Northern Mariana Islands, the U.S. Virgin Islands, or the U.S. Minor Outlying Islands (Midway). In these Island Areas the ZCTA field is blank in the Census 2000 TIGER/Line files. Data users should not use ZCTAs to identify the official USPS ZIP Code for mail delivery. Except in the Island Areas, each Census 2000 tabulation block will have a single ZCTA code that will reflect the majority ZIP Code for addresses within that tabulation block. As a result, ZIP Codes associated with address ranges found in Record Types 1 and 6 may not exactly match the ZCTA. Because addresses and ZIP Codes will not exist within all Census 2000 census tabulation blocks, the U.S. Census Bureau will use automated extension algorithms to close coverage gaps and will assign either a 5- or 3- digit ZCTA code to each Census 2000 tabulation block. The ZCTA delineation process will attempt to assign a 5-digit ZCTA code to areas with no ZIP Code or address data. Where reliable data are unavailable for extensive areas, the ZCTA code may represent the more general 3-digit ZIP Code. The U.S. Census Bureau will be identifying ZCTAs by using a five- character alphanumeric code. The first three characters will represent the 3- digit ZIP Code and may contain leading zeros. For ZCTAs defined only by a 3-digit ZIP Code the last two characters of the ZCTA code will be "XX." For example, ZCTA code "290XX" will represent the generic 3-digit ZIP Code 290 where no 5-digit ZIP Code was available. For ZCTA codes that will reflect the 5-digit ZIP Code, the last two characters of the ZCTA code will be numeric. For example, the ZCTA code "00601" will represent the 5- digit ZIP Code 00601. The ZCTA delineation process will not recognize ZCTA codes ending in "00", such as "29000", as valid 5-digit ZCTA codes. Some water features will have a 3-digit ZCTA code followed by "HH", for example "290HH". These codes will apply only to water features and usually will belong to water features located along the edges of 5-digit ZCTAs. The codes will indicate that the water feature does not clearly fall within one 5-digit ZCTA and is distinct from the 3-digit ZCTA code that will be assigned to land areas. In effect, these codes will identify unassigned water areas. A ZCTA may not exist for every USPS ZIP Code. For instance, a special purpose ZIP Code may represent a point location that does not characterize the majority of the addresses for a Census 2000 tabulation block. Under these circumstances the special purpose ZIP Code will not appear as a ZCTA. For more information on ZCTAs go to URL: http://www.census.gov/geo/ZCTA.zcta.html. ZCTA Code Record Locations Record Type Field Name Description S ZCTA5 ZIP Code Tabulation Area, 2000