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1:1,000,000-Scale County Boundaries of the United States, 2014

Identification Information

Citation
Title
1:1,000,000-Scale County Boundaries of the United States, 2014
Originator
Geological Survey (U.S.)
Publisher
Geological Survey (U.S.)
Place of Publication
Rolla , MO , US
Publication Date
2014-03-01
Identifier
http://purl.stanford.edu/wg010mf7692
Geospatial Data Presentation Form
mapDigital
Collection Title
National Atlas of the United States of America, 1997-2014
Abstract
This polygon shapefile contains the county boundaries of the United States, Puerto Rico, and the U.S. Virgin Islands, by showing the counties as areas. The map layer was created by extracting county polygon features from the CENSUS 2006 TIGER/Line files produced by the U.S. Census Bureau. These files were then merged into a single file. This is a revised version of the July 2012 map layer. This layer is part of the 1997-2014 edition of the National Atlas of the United States.
Purpose
These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:1,000,000-scale data. No responsibility is assumed by the National Atlas of the United States in the use of these data.
Supplemental Information
{"gdaId" : 6065865}
Scale Denominator
1000000
Temporal Extent
Currentness Reference
Publication date
Time Instant
2014-03-01T00:00:00
Bounding Box
West
-179.14734
East
179.77848
North
71.38921
South
17.674396
ISO Topic Category
boundaries
Place Keyword
United States
Alaska
Alabama
Arizona
Arkansas
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York (State)
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington (D.C.)
Washington (State)
West Virginia
Wisconsin
Wyoming
Puerto Rico
United States. Virgin Islands
Place Keyword Thesaurus
geonames
Theme Keyword
Administrative and political divisions
Counties
Theme Keyword Thesaurus
lcsh
Resource Constraints
Use Limitation
None. Acknowledgment of The National Atlas of the United States of America would be appreciated in products derived from these data.
Legal Constraints
Use Limitation
Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the U.S. Geological Survey regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. No responsibility is assumed by the U.S. Geological Survey in the use of these data.
Status
completed
Maintenance and Update Frequency
irregular
Collection
Collection Title
National Atlas of the United States of America, 1997-2014
URL
http://purl.stanford.edu/cv275yx9215
Language
eng
Credit
U.S. Geological Survey. (2014). USGS. 1:1,000,000-Scale County Boundaries of the United States, 2014. Available at: http://purl.stanford.edu/wg010mf7692
Point of Contact
Contact
National Atlas of the United States
Delivery Point
511 National Center
City
Reston
Administrative Area
VA
Postal Code
20192
Email
atlasmail@usgs.gov
Phone
1-888-ASK-USGS (1-888-275-8747)

Spatial Reference Information

Reference System Identifier
Code
4269
Code Space
EPSG
Version
8.6.2

Data Quality Information

Lineage
Process Step
Description
The 1:1,000,000-scale county boundaries were derived from U.S. Census TIGER/Line (Topologically Integrated Geographic Encoding and Reference system) data. The TIGER files were merged and generalized.
Process Date
2007-01-01T00:00:00
Process Step
Description
All the 1:1,000,000-scale map layers were checked for vertical integration. Line positions were adjusted as necessary to remove overlaps. Wherever possible, linear features were separated by 300 meters, but were kept within 500 meters of their true location.
Process Date
2012-01-01T00:00:00
Process Step
Description
The file was projected to an Albers Equal-Area projection, a field was added for square miles and the values calculated using ArcMap, and the file was converted back to geographic coordinates.
Process Date
2012-01-01T00:00:00
Process Step
Description
Data along the Canadian border were adjusted so that the Canadian and U.S. 1:1,000,000-scale data sets can be used together as seamlessly as possible. Problem areas were identified by Natural Resources Canada (NRCan) and edits to the U.S. data were performed by the USGS. To identify problems, the National Atlas 1M Counties 2012 data set was projected to the NRCan working coordinate system, which is a Lambert Conformal Conic projection with standard parallels of 49 and 77 degrees, datum of NAD83, an XY tolerance of 0.001 meters, and an XY resolution of 0.0001 meters. The Canadian and U.S. data sets were displayed together and features were compared across the border. An initial set of comments and suggestions for edits were sent to the USGS by NRCan. NRCan used satellite imagery for reference during the editing process by converting the appropriate National Atlas 1:1,000,000-scale map layers and the 250K Canadian topographic data to KML and loading the KMLs into GoogleEarth. Using the cursor coordinates in the ArcMap status bar, NRCan visually navigated and correlated the ArcMap and GoogleEarth vectors. NRCan exported their findings and sent them to the USGS for correction and (or) further comment. USGS reviewed the Canadian findings and returned the data to NRCan with comments. The U.S. data were either edited, not edited and further explanation was requested, or not edited and changes were suggested for the Canadian data. This process was repeated until both NRCan and USGS felt that the data were satisfactorily harmonized.
Process Date
2013-01-01T00:00:00
Process Step
Description
The map layer was saved in shapefile and in file geodatabase formats.
Process Date
2013-01-01T00:00:00
Process Step
Description
The county areas in the file were combined into multi-part polygons, one for each county including associated islands. Population values were added from the 2010 Census information. The data were projected by region to the National Atlas Albers Equal Area Conic projection, fields were added for the perimeter measurement and square miles, the values were calculated using ArcMap, and the data were converted back to geographic coordinates. The Albers Equal Area Conic parameters used are available on request.
Process Date
2013-01-01T00:00:00
Source
Title
National Topographic System Maps (1:250 000)
Originator
Government of Canada, Natural Resources Canada, Mapping Information Branch
Publisher
Government of Canada
Description
  Positional reference 
Source
Title
2006 Second Edition TIGER/Line files - Boundaries
Publication Date
2007-01-01
Originator
U.S. Census Bureau
Description
Spatial and attribute information
Source
Title
Atlas of Canada National Scale Data 1:1,000,000 - Boundary Lines
Publication Date
2013-11-08
Originator
Government of Canada, Natural Resources Canada, Mapping Information Branch
Publisher
Government of Canada
Description
Spatial information
Source
Title
1:1,000,000-Scale County Boundaries of the United States
Publication Date
2012-07-01
Originator
National Atlas of the United States
Publisher
National Atlas of the United States
Description
Spatial and attribute information
Source
Title
Legal Boundary Points
Originator
Government of Canada, Natural Resources Canada, Geomatics Canada, Surveyor General's Branch, International Boundary Commission
Description
Spatial data
Source
Title
Legal Boundary Points
Originator
Government of Canada, Natural Resources Canada, Geomatics Canada, Surveyor General's Branch, International Boundary Commission
Description
Spatial data
Source
Title
1:1,000,000-Scale National Atlas map layers and other quality control files
Originator
National Atlas of the United States
Description
Spatial information

Distribution Information

Format Name
Shapefile
Distributor
Stanford Geospatial Center
Online Access
http://purl.stanford.edu/wg010mf7692
Protocol
http
Name
countyp010g.shp
Function
download

Content Information

Feature Catalog Description
Compliance Code
false
Language
eng
Included With Dataset
true
Feature Catalog Citation
Title
Feature catalog for 1:1,000,000-Scale County Boundaries of the United States, 2014
Feature Catalog Identifier
3e2517f8-c228-4d7f-8e2c-e56bc9a5e508

Spatial Representation Information

Vector
Topology Level
geometryOnly
Vector Object Type
composite
Vector Object Count
3233

Metadata Reference Information

Hierarchy Level
dataset
Metadata File Identifier
edu.stanford.purl:wg010mf7692
Parent Identifier
http://purl.stanford.edu/cv275yx9215.mods
Dataset URI
http://purl.stanford.edu/wg010mf7692
Metadata Date Stamp
2015-11-10
Metadata Standard Name
ISO 19139 Geographic Information - Metadata - Implementation Specification
Metadata Standard Version
2007
Character Set
utf8
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