Metadata for Montana 1990 Census Block Group Boundaries Metadata for Montana 1990 Census Block Group Boundaries

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Identification Information:

Citation:

Originator: Montana State Library

Publication date: 05/14/1999

Title: Montana 1990 Census Block Group Boundaries

Publication place: Helena, Montana
Publisher: Montana State Library

Other citation details:

The former name of the data set on the NRIS web site was "ab135"

Online linkage: https://ftpgeoinfo.msl.mt.gov/Data/Spatial/NonMSDI/Collections/Census/blkgrp1990.zip

Larger Work Citation:

Title: Montana State Library Census Data Collection, 1990-2010
Online linkage: https://mslservices.mt.gov/Geographic_Information/Data/DataList/datalist_Details.aspx?did={77211e26-cfa9-4a7b-b8f8-09d567c1d131}

Browse graphic file name: https://ftpgeoinfo.msl.mt.gov/Documents/Maps/Thumbnails/20031118_603_thumb.jpg
Browse graphic file description: Thumbnail image of 1990 Block Group population density map

Browse graphic file name: https://ftpgeoinfo.msl.mt.gov/Documents/Maps/Individual/20031118_603_2003_MTPopDensitybyBlock.gif
Browse graphic file description: Map of 1990 Block Group population density

Abstract:

Block Group derived from 1992 U.S. Census Bureau TIGER files, with total 1990 Census population counts.

Census Block Groups are the regions for which data is available from the long questionnaire sent to 1/6th of the people in the 1990 Census. To link this data to the Summary Tape File 3A data from the Census, you must relate the UNIQUEID field to a field from the STF3A file that is a combination of the COUNTY, TRACTBNA, and BLCKGR fields.

Time period of content:

Calendar date: 1990
Currentness reference: Publication Date

Status:

Progress: Complete

Access constraints: None

Use constraints:

The Montana State Library provides this product/service for informational purposes only. The Library did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their purposes. The Library provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the Library be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The Library makes these data and services available as a convenience to the public, and for no other purpose. The Library reserves the right to change or revise published data and/or services at any time.

Point of contact:

Montana State Library
PO Box 201800
Helena, Montana 59620-1800
Telephone: 406-444-5354
TDD/TTY telephone: Montana Relay 711
Fax: 406-444-0266
E-Mail: geoinfo@mt.gov

Data Quality Information:

Attribute accuracy report:

Block Group numbers were copied directly from the 1992 TIGER files, and are believed to be accurate.

Completeness report: Data set is complete

Horizontal Positional Accuracy Report:

Approximate horizontal accuracy is 51 meters, assuming source data meets National Map Accuracy Standards.

Lineage:

Source information:

Originator: U.S. Census Bureau
Publication date: 1992
Title: 1992 Tiger/Line Files
Edition: 1992
Source scale denominator: 100000
Source contribution: The data set is a sub-set of this source.
Calendar date: 1992

Process step:

Convert TIGER files to Arc/Info format and project them from geographic coordinates to Albers.


Process date: 05/01/1996

Process step:

Dissolve TIGER county coverages on the blockgrp attribute. Summarize the population totals from the individual Census Blocks.


Process date: 05/14/1996

Process step:

Add the county FIPS code to each county attribute table so that the block groups will have a unique attribute when all the counties are joined. Mapjoin all the counties into a single coverage.


Process date: 05/14/1999

Process step:

Bring the UniqueID field back into the shapefile from the coverage version of the layer. It had gone missing somehow. Add the population density field.


Process date: 01/08/2014

Spatial Data Organization Information:

Point and vector object information:

SDTS object type: G-polygon

SDTS object count: 1024

Spatial Reference Information:

Horizontal coordinate system definition:

Grid coordinate system name: State Plane Coordinate System 1983

SPCS zone identifier: 2500

Lambert conformal conic:

Standard parallel: 45
Standard parallel: 49
Longitude of central meridian: -109.5
Latitude of projection origin: 44.25
False easting: 600000.00000
False northing: 0.00000

Planar distance units: meters

Geodetic model:

Horizontal datum name: North American Datum of 1983
Ellipsoid name: Geodetic Reference System 80
Semi-major axis: 6378137
Denominator of flattening ratio: 298.257

Entity and Attribute Information:

Entity type label: blockgrp.dbf

Entity type definition: Polygon Attribute Table

Attribute label: FID

Attribute definition: Shapefile sequence number

Attribute label: Shape

Attribute definition: Feature geometry

Attribute label: Area

Attribute definition: area of the polygon in square meters

Attribute label: Perimeter

Attribute definition: perimeter of the polygon in meters

Attribute label: AB135_

Attribute definition: Sequence number from original coverage version of the data

Attribute label: AB135_ID

Attribute definition: ID number from original coverage version of the data

Attribute label: COUNTY

Attribute definition: County FIPS Code

Attribute label: UniqueID

Attribute definition:: String that uniquely identifies a block group within Montana.
This is the link to the the combination of the COUNTY, TRACTBNA, and BLCKGR fields from the Census Summary Tape File 3A data tables.

Attribute label: Population