The U. The caller can also provide the data and the comparison operation to request hatching over any areas. The location id provided in the data determines the geographic level of the mapping. If the location id references the U. Seer Registry areas, the Seer Registry area identifier used to link the data to the geographical areas, then the location id is the Seer Registry name or abbreviation. The package uses modified boundary data from the and U. Census to reduce the storage requirements and improve drawing speed.
Census and boundary data for the regional, state, Seer Registry, and county levels. Six supplement packages contain the census tract boundary data see manual for more details. Supplemental U. The data contained in this package is derived from U.
Census data and is in public domain. 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 American Indian tribal member individual trust land or allotment. Trust lands may be located on onreservation or off an American Indian reservation off-reservation. The Census Bureau recognizes and tabulates data for reservations and off-reservation trust lands ORTLs because American Indian tribes have governmental authority over these lands.
Tribal governmental authority generally is not attached to lands located off the reservation until the lands are placed in trust status. A tribal government appointed liaison provides the name and boundaries of their ORTLs. Based on a compact between the federal government and the new State of Hawaii in , the Hawaii Admission Act vested land title and responsibility for the program with the State.
The 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 Hawaii from which the lands were designated, or from the local name for an area. Being lands held in trust, Hawaiian home lands are treated as equivalent to off-reservation trust land areas with an AIANNH area trust land indicator coded as T.
Each Hawaiian home land area is assigned a nationally unique four-digit census code ranging from through based on the alphabetical sequence of each HHL name. The Census Bureau designates both legal and statistical joint-use areas as unique geographic entities for the purpose of presenting statistical data. Each is assigned a nationally unique four-digit census code ranging from through , a five-digit FIPS code, and a nationally unique eight-digit ANSI code.
ANVSAs are intended to represent the relatively densely settled portion of each ANV and ideally should include only an area where Alaska Natives, especially members of the defining ANV, represent a significant proportion of the population during at least one season of the year at least three consecutive months. ANVSAs also ideally should not contain large areas that are primarily unpopulated or do not include concentrations of Alaska Natives, especially members of the defining ANV.
Statistical joint-use areas only apply to overlapping Oklahoma tribal statistical areas. Oklahoma Tribal Statistical Areas OTSAs are statistical entities identified and delineated by the Census Bureau in consultation with federally recognized American Indian tribes that formerly had a reservation in Oklahoma.
The boundary of an OTSA is generally that of the former reservation in Oklahoma, except where modified by agreements with neighboring federally recognized tribes that are eligible to delineate an OTSA. Tribal subdivisions can exist within the statistical Oklahoma tribal statistical areas. Each OTSA is assigned a nationally unique four-digit census code ranging from through based on the alphabetical sequence of each OTSAs name, except that the joint -use areas appear at the end of the code range.
SDTSAs are identified and delineated for the Census Bureau by a state liaison identified by the governor's office in each state. SDTSAs 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.
Tribal Designated Statistical Areas TDSAs are statistical entities identified and delineated for the Census Bureau by federally recognized American Indian tribes that do not currently have a reservation or offreservation trust land.
A TDSA generally encompasses a compact and contiguous area that contains a concentration of individuals who identify with the delineating federally recognized American Indian tribe and in which there is structured or organized tribal activity. The census codes are assigned in alphabetical order in assigned ranges by AIANNH area type nationwide, except that joint-use areas appear at the end of their applicable code range. ORTLs are assigned the same code as the reservation with which they are associated.
ORTLs associated with tribes that do not have a reservation are assigned codes based on their tribal name. Tribal subdivisions are known as additions, administrative areas, areas, chapters, county districts, districts, or segments. The Census Bureau obtains the boundary and name information for tribal subdivisions from the federally recognized tribal governments.
Tribal census tracts are conceptually similar and equivalent to standard census tracts. Tribal census tracts generally have at least 1, persons or housing units, and no more than 8, persons or 3, housing units, with an optimal size of 4, persons or 1, housing units. Because is the first Census for which this coding scheme was used, no tribal census tracts currently have suffixes, in other words they all have a suffix of Tribal census tract codes all begin with the letter T and are followed by three digits and the two-digit suffix, for example T Tribal Census Tract Namesthe tribal census tract code also acts as its name, with the suffix only appended if required.
The NAME field contains the tribal census tract name as displayed in Census Bureau printed reports and on mapping products. The name will consist of the first four characters T followed by three digits, including any leading or trailing zeros and a decimal point followed by the two-digit suffix if the suffix is something other than When the suffix is only zeros, the decimal point and suffix in the tribal tract are omitted from the name.
For example, tribal census tract code T has a tribal census tract name of T Tribal Block Group geography and attributes are available in the following shapefile: Tribal Block Group National Shapefile Current Tribal block groups are clusters of blocks within the same tribal census tract. Unlike standard block groups, the cluster of blocks that comprises each tribal block group will not necessarily begin with the same first number of their four-digit census block number, but may contain blocks from several different standard census block groups.
Tribal block groups are intended to generally contain between and 3, persons or between and 1, housing units. A tribal block group usually covers a contiguous area but in some cases may consist of more than one discrete area. Tribal block groups are uniquely named within tribal tracts. Tribal block group names and codes are identical and are a single capital letter character from A to K except for the letter I and must be unique within each tribal census tract.
There is no relationship between the tribal block group identifier and the numbering of the census blocks that form the tribal block group. A tribal block group will always be identified in conjunction with the tribal census tract within which it is contained, for example TA. Block geography and attributes are available in the following shapefile: Block State-based Shapefile Current Census Blocks are statistical areas bounded on all sides by visible features, such as streets, roads, streams, and railroad tracks, and by non-visible boundaries such as city, town, township, and county limits, and short line-of-sight extensions of streets and roads.
Generally, census blocks are small in area;. In remote areas census blocks may encompass hundreds of square miles. Blocks never cross county or census tract boundaries See Figures 3 and 4. They do not cross the boundaries of any entity for which the Census Bureau tabulates data, including American Indian, Alaska Native, and Native Hawaiian areas, congressional districts, county subdivisions, places, state legislative districts, urbanized areas, urban clusters, school districts, voting districts, or ZIP Code Tabulation Areas ZCTAs or some special administrative areas such as military installations, and national parks and monuments.
The first digit of the tabulation block number identifies the block group. Current Geography To accommodate changes in legal entity boundaries occurring after January 1, , the Census Bureau assigns a current alphabetic suffix for a Census block number. The current suffixes for Census block numbers are not permanent and will change with each annual cycle of current block suffixing. Due to potential updates to the codes, it is important not to mix Census geographic codes with current geographic codes.
Block group geography and attributes are available in the following shapefile: Block Group State-based Shapefile Current Block groups are clusters of blocks within the same census tract that have the same first digit of their 4digit census block number. For example, blocks , , ,. Block groups delineated for the Census generally contain between and 3, people. The Census Bureau delineated block groups only where a local or tribal government declined to participate or where the Census Bureau could not identify a potential local participant.
A block group usually covers a contiguous area. Each census tract contains at least one block group and block groups are uniquely numbered within census tract. Within the standard census geographic hierarchy, block groups never cross county or census tract boundaries, but may cross the boundaries of county subdivisions, places, urban areas, voting districts, congressional districts, and American Indian, Alaska Native, and Native Hawaiian areas. Block groups have a valid range of 0 through 9.
Block groups beginning with a zero 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 Census Bureau delineated some census tract boundaries along the shoreline or just offshore. The Census Bureau assigned a default census tract number of zero and block group of zero to the offshore areas not included in regularly numbered census tract areas.
Census tract geography and attributes are available in the following shapefile: Census Tract State-based Shapefile Current Census tracts are small, relatively permanent statistical subdivisions of a county or equivalent entity, and are reviewed and updated by local participants prior to each decennial census as part of the Census Bureaus Participant Statistical Areas Program.
The Census Bureau updates 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 tracts generally have a population size between 1, and 8, people with an optimum size of 4, people.
The spatial size of census tracts varies widely depending on the density of settlement. Census tracts 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 boundaries generally follow visible and identifiable features. They 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 always are census tract boundaries in the standard census geographic hierarchy. 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 Tract Codes and NumbersCensus tract numbers have up to a 4-digit basic number and may have an optional 2-digit suffix; for example, The census tract numbers used as names eliminate any leading zeroes and append a suffix only if required.
The 6-character numeric census tract codes, however, include leading zeroes and have an implied decimal point for the suffix. Census tract codes range from to and are unique within a county or equivalent area.
The Census Bureau reserved the census tract numbering range of to for use by American Indian area participants in situations where an American Indian entity crosses county or state lines. The Census Bureau assigned a census tract code of to some coastal and Great Lakes water and territorial sea, rather than extend the census. This allowed the Census Bureau to provide complete census tract coverage of Current water areas in territorial seas and the Great Lakes. Because of updates since , there are census tracts with code that now contain land.
Census tract suffixes may range from. The 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 renumbering of, the census tracts. Changes to individual census tract boundaries usually do not result in census tract numbering changes.
Relationship to Other Geographic EntitiesWithin the standard census geographic hierarchy, census tracts never cross state or county boundaries, but may cross the boundaries of county subdivisions, places, urban areas, voting districts, congressional districts, and American Indian, Alaska Native, and Native Hawaiian areas. Congressional district geography and attributes are available in the following shapefile: th Congressional District National Shapefile Congressional Districts are the areas from which people are elected to the U.
House of Representatives. After the apportionment of congressional seats among the states based on decennial census population counts, each state is responsible for establishing the boundaries of the 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 th Congressional District shapefile contains the areas in effect January to and are the tabulation congressional districts for the Census.
Each state has a minimum of one representative in the U. Virgin Islands have a non-voting delegate in the Congress. Congressional districts are numbered uniquely within state. The District of Columbia, Puerto Rico and the Island areas have the code of 98, which identifies their status with respect to representation in Congress: 01 to 53Congressional district codes 00At large single district for state 98Nonvoting delegate.
Consolidated city geography and attributes are available in the following shapefile: Consolidated City State-based Shapefile Current Consolidated CityA 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. This action results 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 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.
Consolidated City Balance Portions refer to the areas of a consolidated city not included in another separately incorporated place. The area of the consolidated city that is not in Walkerville city is assigned to Butte-Silver Bow balance. The name always includes the balance identifier. Balance portions of consolidated cities are included in the Place shapefiles.
County and equivalent entity geography and attributes are available in the following shapefile: County and Equivalent Entity National Shapefile Current Counties and Equivalent Entities are primary legal divisions. In most states, these entities are termed counties. In Louisiana, these divisions are known as parishes. In Alaska, the equivalent entities are the organized boroughs, city and boroughs, and municipalities, and for the unorganized areas, census areas. The latter are delineated cooperatively for statistical purposes by the State of Alaska and the 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 county equivalent entities for purposes of data presentation. The District of Columbia and Guam have no primary divisions and each area is considered a county equivalent entity for purposes of data presentation. The Census Bureau treats the following entities as equivalents of counties for purposes of data presentation: municipios in Puerto Rico, districts and islands in America Samoa, municipalities in the Commonwealth of the Northern Mariana Islands, and islands in the U.
Virgin Islands. Counties form the building blocks for CBSAs, thus county records can be merged to form these areas without having to acquire the individual CBSA shapefiles.
County subdivision geography and attributes are available in the following shapefile: County Subdivision State-based Shapefile Current County subdivisions are the primary divisions of counties and their equivalent entities for the reporting of decennial census data. They include census county divisions, census subareas, minor civil divisions, and unorganized territories.
MCDs include areas variously designated as American Indian reservations, assessment districts, barrios, barrios-pueblo, boroughs, census subdistricts, charter townships, commissioner districts, counties, election districts, election precincts, gores, grants, locations, magisterial districts, parish governing authority districts, plantations, precincts, purchases, supervisor's districts, towns, and townships.
The District of Columbia has no primary divisions, and the incorporated place of Washington is treated as an equivalent to an MCD for statistical purposes it is also considered a state equivalent and a county equivalent. The ANSI codes also match for those entities. In other states, incorporated places are part of the MCDs in which they are located, or the pattern is mixedsome incorporated places are independent of MCDs and others are included within one or more MCDs. The Census Bureau presents data for these MCDs in all data products for which place data are provided.
Statistical Entities Census County Divisions CCDs are areas delineated by the Census Bureau in cooperation with state officials and local officials for statistical purposes. CCDs are not governmental units and have no legal functions. 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. The files have been created to simplify the effort of downloading and merging the county level shp files available from ftp2.
Have also added the associated county and state information to the files. Sign up to join this community. The best answers are voted up and rise to the top.
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