County Boundaries of the United States, 2001

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How should this data set be cited?

   National Atlas of the United States, 200506, County Boundaries of the United States, 2001: National Atlas of the United States, Reston, VA.

   Online Links:

   • <http://nationalatlas.gov/atlasftp.html?openChapters=chpbound#chpbound>

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: 170

   East_Bounding_Coordinate: -64

   North_Bounding_Coordinate: 72

   South_Bounding_Coordinate: 17

3. What does it look like?

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 1972

   Ending_Date: 2001

   Currentness_Reference: Ground condition

5. What is the general form of this data set?

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

      Indirect_Spatial_Reference:

      U.S. Department of Commerce, 1987, Codes for the Identification of the States, the District of Columbia and the Outlying Areas of the United States, and Associated Areas (FIPS 5-2): Washington, DC, National Institute of Standards and Technology.

      U.S. Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas (FIPS 6-4): Washington, DC, National Institute of Standards and Technology.

      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • GT-polygon composed of chains (6138)

   2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000278. Longitudes are given to the nearest 0.000278. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is GRS1980.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257222.
      

7. How does the data set describe geographic features?

   County (described by Countyp020.dbf)

   The second order division of a nation, such as a parish, borough, municipio, judicial division, and independent cities in Maryland, Missouri, Nevada, and Virginia. (Source: National Atlas of the United States)

   Shape

   The representation of the entity in the data. (Source: National Atlas of the United States)

   Value	Definition
   Polygon	2-dimensional element

   Area

   The size of the shape in coverage units. In the distributed file, coverage units represent square decimal degrees. (Source: National Atlas of the United States)

   Range of values
   Minimum:	0.000
   Maximum:	73.832

   Perimeter

   The perimeter of the shape in coverage units. In the distributed file, coverage units represent decimal degrees. (Source: National Atlas of the United States)

   Range of values
   Minimum:	0.010
   Maximum:	87.571

   Countyp020

   Internal feature number. (Source: National Atlas of the United States)

   Range of values
   Minimum:	2
   Maximum:	6139

   State

   The two-character abbreviation for the name of the State or State equivalent in which the county is located. (Source: National Atlas of the United States)

   Formal codeset
   Codeset Name:	Codes for the Identification of the States, the District of Columbia and the Outlying Areas of the United States, and Associated Areas; (Federal Information Processing Standard (FIPS) 5-2): Washington, DC, National Institute of Standards and Technology.
   Codeset Source:	U.S. Department of Commerce

   County

   The name of the county or county equivalent. (Source: National Atlas of the United States)

   Value	Definition
   <blank>	Water areas of the United States for which a county designation is not reported.

   Formal codeset
   Codeset Name:	Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas; (Federal Information Processing Standard (FIPS) 6-4): Washington, DC, National Institute of Standards and Technology.
   Codeset Source:	U.S. Department of Commerce

   Fips

   The 5-digit FIPS code of the county or county equivalent. Codes ending in 000 indicate water areas for which a county designation is not reported. (Source: National Atlas of the United States)

   Formal codeset
   Codeset Name:	Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas; (Federal Information Processing Standard (FIPS) 6-4): Washington, DC, National Institute of Standards and Technology.
   Codeset Source:	U.S. Department of Commerce

   State_fips

   The 2-digit FIPS code of the State or State equivalent. (Source: National Atlas of the United States)

   Formal codeset
   Codeset Name:	Codes for the Identification of the States, the District of Columbia and the Outlying Areas of the United States, and Associated Areas; (Federal Information Processing Standard (FIPS) 5-2): Washington, DC, National Institute of Standards and Technology.
   Codeset Source:	U.S. Department of Commerce

   Square_mil

   The size of the county or county equivalent in square miles. It was calculated by summing values in the area field for each county, which is in square meters, and multiplying the results by 0.0000003681. These values may not match those reported by State or county governments, especially in coastal areas. (Source: National Atlas of the United States)

   Range of values
   Minimum:	1.976
   Maximum:	146099.233

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • National Atlas of the United States

2. Who also contributed to the data set?

3. To whom should users address questions about the data?
   Woodley Chu
   National Atlas of the United States
   12201 Sunrise Valley Dr
   Reston, VA 20192
   

   703-648-6375 (voice)
   atlasmail@usgs.gov
   

Why was the data set created?

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 1:2,000,000-scale data. No responsibility is assumed by the National Atlas of the United States in the use of these data.

How was the data set created?

1. From what previous works were the data drawn?

   2MILBD (source 1 of 18)

   U.S. Geological Survey, 1995, 1:2,000,000-scale Digital Line Graph Data - Boundaries: U.S. Geological Survey, Reston, VA.

   Type_of_Source_Media: CD-ROM

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   ATLAS-CNTY98 (source 2 of 18)

   National Atlas of the United States, 1998, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   ATLAS-HY9903 (source 3 of 18)

   National Atlas of the United States, 1999, Hydrography Features of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial information

   ATLAS-CNTY9903 (source 4 of 18)

   National Atlas of the United States, 19990326, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   1:100,000-scale base maps (source 5 of 18)

   U.S. Geological Survey, Unknown, 1:100,000-scale USGS topographic maps: U.S. Geological Survey, Reston, VA.

   Type_of_Source_Media: Paper

   Source_Scale_Denominator: 100000

   Source_Contribution: Spatial and attribute information

   Geographic Names Information System (source 6 of 18)

   U.S. Geological Survey, 1999, Geographic Names Information System: U.S. Geological Survey, Reston, VA.

   Type_of_Source_Media: Online

   Source_Contribution: Attribute information

   ATLAS-CNTY9911 (source 7 of 18)

   National Atlas of the United States, 199911, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   ATLAS-CNTY0102 (source 8 of 18)

   National Atlas of the United States, 200102, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   BROOM (source 9 of 18)

   City and County of Broomfield, CO, Unpublished material, County Boundary.

   Type_of_Source_Media: Electronic mail system

   Source_Contribution: Spatial and attribute information

   CO99_D00 (source 10 of 18)

   Department of Commerce, Census Bureau, Geography Division, 200001, 2000 County and County Equivalent Areas: Department of Commerce, Census Bureau, Geography Division, Washington, DC.

   Online Links:

   • <http://www.census.gov/geo/www/cob/co2000.html>

   Type_of_Source_Media: Online

   Source_Contribution: Spatial information

   ATLAS-CNTY0202 (source 11 of 18)

   National Atlas of the United States, 200202, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   ATLAS-CNTY0207 (source 12 of 18)

   National Atlas of the United States, 200207, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   FIPS_DOC (source 13 of 18)

   National Institute of Standands, Information Technology Laboratory, 19900831, Federal Information Processing Standard 6-4 (FIPS 6-4), Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, 1990 August 31: National Institute of Standands and Technology, Information Technology Laboratory, Gaithersburg, MD.

   Online Links:

   • <http://www.itl.nist.gov/fipspubs/fip6-4.htm>

   Type_of_Source_Media: Online

   Source_Contribution: Spatial information

   ATLAS-CNTY0208 (source 14 of 18)

   National Atlas of the United States, 200208, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   GNIS04 (source 15 of 18)

   U.S. Geological Survey, 2004, Geographic Names Information System: U.S. Geological Survey, Reston, VA.

   Type_of_Source_Media: Online

   Source_Contribution: Attribute information

   ATLAS-CNTY0411 (source 16 of 18)

   National Atlas of the United States, 200411, County Boundaries of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

   GNIS05 (source 17 of 18)

   U.S. Geological Survey, 2005, Geographic Names Information System: U.S. Geological Survey, Reston, VA.

   Type_of_Source_Media: Online

   Source_Contribution: Attribute information

   ATLAS-hydro (source 18 of 18)

   National Atlas of the United States, 200301, Streams and Waterbodies of the United States: National Atlas of the United States, Reston, VA.

   Type_of_Source_Media: Online

   Source_Scale_Denominator: 2000000

   Source_Contribution: Spatial and attribute information

2. How were the data generated, processed, and modified?

   Date: 1998 (process 1 of 10)

   The 2MILBD data files were originally digitized by the National Mapping Division based on the sectional maps contained in 'The National Atlas of the United States of America' published by the USGS in 1970. The sectional maps were updated during 1978-1981 and digitized in the early 1980's. The data were updated again in the early 1990's by the USGS and published on CD-ROM in 1995 as State DLGs. Using Arc/INFO software, the updated DLG optional-format files were converted to Arc/INFO coverages using the DLGARC command. Only county boundaries and attribute information were extracted from the boundaries DLG layer for inclusion in this national coverage. The county boundary lines that crossed open water were excluded for graphic purposes and polygons that represented islands were attributed with the appropriate county information. The individual State coverages were then merged together using the Arc/INFO command MAPJOIN. "Slivers" created during the MAPJOIN process were identified and deleted using the ELIMINATE command. In 1998, the delineation of the boundary of Mojave County, AZ was corrected. Minor modifications were also made to boundaries in Alaska.

   Data sources used in this process:

   • 2MILBD

   Data sources produced in this process:

   • ATLAS-CNTY98

   Date: Mar-1999 (process 2 of 10)

   The spatial features were compared against the National Atlas hydrography layer (ATLAS-HY9903) and modified where necessary. Incorrect attributes were corrected. Yellowstone County was deleted and the boundaries for Gallatin and Park Counties were adjusted to absorb the area of Yellowstone National Park. Puerto Rico and the U.S. Virgin Islands were added.

   Data sources used in this process:

   • ATLAS-HY9903
   • ATLAS-CNTY98
   • 2MILBD

   Data sources produced in this process:

   • ATLAS-CNTY9903

   Date: Nov-1999 (process 3 of 10)

   Several boundary adjustments were made to counties in Alaska, Nebraska, Oklahoma, Texas, and Virginia. Dade County, Florida was changed to Miami-Dade County and the FIPS code was changed to 12086.

   Data sources used in this process:

   • ATLAS-CNTY9903
   • 1:100,000-scale base maps
   • Geographic Names Information System

   Data sources produced in this process:

   • ATLAS-CNTY9911

   Date: Feb-2001 (process 4 of 10)

   The county name was corrected for the Grass Cay and Mingo Cay polygons in the U.S. Virgin Islands. The State field was changed from names to two-character abbreviations, and a field for State FIPS was added.

   Data sources used in this process:

   • ATLAS-CNTY9911

   Data sources produced in this process:

   • ATLAS-CNTY0102

   Date: Dec-2001 (process 5 of 10)

   The newly formed City and County of Broomfield, Colorado was added to the map layer.

   Data sources used in this process:

   • ATLAS-CNTY0102
   • BROOM

   Date: Jan-2002 (process 6 of 10)

   The boundary of Juneau Borough, Alaska was modified to include approximately 61,000 acres of northern Admiralty Island. Data from the Census Bureau's county boundary file of Alaska was extracted and generalized to a scale of 1:2,000,000.

   The boundary of Denver County, Colorado was modified to include the area occupied by Denver International Airport. Additional minor corrections were made to Denver County and Adams County. All corrections were made using data from the Census Bureau's county boundary file of Colorado.

   Finally, county attribution was removed from the Niagara River between Lake Ontario and Lake Erie.

   Data sources used in this process:

   • CO99_D00
   • ATLAS-CNTY0102

   Data sources produced in this process:

   • ATLAS-CNTY0202

   Date: Jul-2002 (process 7 of 10)

   Boundary adjustments were made between the following counties or county equivalents:

   1) Navajo and Coconino in Arizona
   2) Tuolumne and Mono in California
   3) Lake and Chaffee in Colorado
   4) Gulf and Franklin in Florida
   5) Plaquemines Parish and Jefferson Parish in Louisiana
   6) Mora and Taos in New Mexico
   7) Otero and Chaves in New Mexico
   8) Canovanas Municipio and Loiza Municipio in Puerto Rico
   9) Tipton and Shelby in Tennesee
   10) Loving and Winkler in Texas
   11) Pecos and Terrell in Texas
   12) Kerr and Bandera in Texas
   13) Real and Bandera in Texas
   14) San Patricio and Nueces in Texas
   15) Sanpete and Jab in Utah
   16) Harrisonburg City and Rockingham County in Virginia
   17) Staunton City and Augusta County in Virginia
   18) Lynchburg City and Campbell County in Virginia
   19) Danville City and Pittsylvania County in Virginia
   
   

   Numerous additional minor boundary adjustments were made throughout the country. In Puerto Rico, Florida Municipio was added and an offshore island was added to Ponce Municipio. A extra polygon within Vega Baja Municipio was merged with the rest of the municipio.

   An attribute containing the area in square miles for the county was added. It was calculated by summing values in the area field for each county, which is in square meters, and multiplying the results by 0.0000003681.

   Data sources used in this process:

   • 1:100,000-scale base maps
   • CO99_D00
   • ATLAS-CNTY0202

   Data sources produced in this process:

   • ATLAS-CNTY0207

   Date: Aug-2002 (process 8 of 10)

   According to the change notice in FIPS_DOC, the independent city (county-equivalent) of Clifton Forge, Virginia, was reverted to town status and is an incorporated place within Alleghany County. Clifton Forge, Virginia (FIPS code 560) was deleted. The FIPS county code of 005 for Alleghany County did not change.

   Data sources used in this process:

   • ATLAS-CNTY0207
   • FIPS_DOC

   Data sources produced in this process:

   • ATLAS-CNTY0208

   Date: Nov-2004 (process 9 of 10)

   The following county names were edited based on the GNIS database: DeBaca NM, DeKalb AL, DeKalb GA, DeKalb IL, DeKalb MO, DeKalb TN, DeSoto FL, DeSoto MS, DeWitt TX, DuPage IL, LaMoure ND, Saint Mary's MD

   Data sources used in this process:

   • ATLAS-CNTY0208
   • GNIS04

   Data sources produced in this process:

   • ATLAS-CNTY0411

   Date: May-2005 (process 10 of 10)

   Maryland's Queen Anne's County had the apostrophe added where missing and the following county names in Alaska were edited based on the GNIS database: Anchorage Municipality, Juneau City and Borough, Sitka City and Borough, Yakutat City and Borough. In addition, two line segments along the Texas/Mexico border were modified to align to ATLAS-hydro.

   Data sources used in this process:

   • ATLAS-CNTY0411
   • GNIS05
   • ATLAS-hydro

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?

2. How accurate are the geographic locations?

3. How accurate are the heights or depths?

4. Where are the gaps in the data? What is missing?

   This map layer includes county boundaries for all 50 States, Puerto Rico, and the U.S. Virgin Islands. Data completeness generally reflects the content of the original DLG files.

5. How consistent are the relationships among the observations, including topology?

   The map layer was checked for topological consistency using the Arc/INFO command BUILD. No other checks for logical consistency were performed on this map layer.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None

Use_Constraints:

None. Acknowledgment of the National Atlas of the United States of America would be appreciated in products derived from these data.

1. Who distributes the data set? (Distributor 1 of 1)
   Earth Science Information Center, U.S. Geological Survey
   507 National Center
   Reston, VA 20192
   

   1-888-ASK-USGS (1-888-275-8747) (voice)
   

   Contact_Instructions:

   In addition to the address above there are other ESIC offices throughout the country. A full list of these offices is at <http://ask.usgs.gov/esic_index.html>.

2. What's the catalog number I need to order this data set?

3. What legal disclaimers am I supposed to read?

   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.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	ESRI Shapefile
     Network links:	<http://nationalatlas.gov/atlasftp.html?openChapters=chpbound#chpbound>

     Data format:	SDTS
     Network links:	<http://nationalatlas.gov/atlasftp.html?openChapters=chpbound#chpbound>

   • Cost to order the data: There is no charge for the map layer.

Who wrote the metadata?

Dates:

Last modified: 30-May-2006

Metadata author:

Peg Rawson
National Atlas of the United States
12201 Sunrise Valley Dr
Reston, VA 20192

703-648-4183 (voice)
atlasmail@usgs.gov

Metadata standard:

FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)