Federal and State managed lands in California and portions northwest Nevada

Frequently-asked questions:


What does this data set describe?

Title:
Federal and State managed lands in California and portions northwest Nevada

Abstract:
The LND_SurfaceEstate data is a geodatabase illustrating the location of Federal and State managed lands in California and portions northwest Nevada. The data is developed and maintained at the BLM California State Office in Sacramento.  The focus of the data development efforts are on accurately depicting the locations of BLM managed lands.  Private and non-governmental lands are categorized as unclassified.   Other Federal agencies, the State of California , and numerous County governments contribute much of the information and data incorporated into this geodatabase.  Data for lands in Nevada were obtained from the Bureau of Land Management, Reno, Nevada.

Supplemental information:
The LND_SurfaceEstate data is edited and maintained in a single polygon feature class.  Whenever possible, BLM lands are constructed from the Public Land Survey System (PLSS), also available to the public (PublicLandSurvey.gdb).  Alignment of BLM data with the PLSS is a continual process, as the accuracy and density of PLSS data continues to improve and develop.  Issues of misalignment with the PLSS are more common with non-BLM management areas.  These discrepancies are being addressed at the BLM California State office based on U.S. Department of Interior priorities throughout the State of California.

  1. How should this data set be cited?

    BLM, California State Office, Mapping Sciences, 5/15/2009, Federal and State managed lands in California and portions northwest Nevada .

    Online links:
  2. What geographic area does the data set cover?

    Bounding coordinates:
    West: -124.550821
    East: -113.587358
    North: 42.117038
    South: 32.452856

  3. What does it look like?

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

    Calendar date: 5/15/2009
    Currentness reference:
    Updated frequently and as required

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

    Geospatial data presentation form: vector digital data

  6. How does the data set represent geographic features?

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

      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • G-polygon (38526)
      • G-polygon (410)
      • G-polygon (410)
      • G-polygon (43511)

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

      The map projection used is Transverse Mercator.

      Projection parameters:
      Scale factor at central meridian: 0.999400
      Longitude of central meridian: -119.000000
      Latitude of projection origin: 37.000000
      False easting: 500000.000000
      False northing: 1500000.000000

      Planar coordinates are encoded using coordinate pair.
      Abscissae (x-coordinates) are specified to the nearest 0.000100.
      Ordinates (y-coordinates) are specified to the nearest 0.000100.
      Planar coordinates are specified in meters.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

      Vertical coordinate system definition:
      Altitude system definition:
      Altitude resolution: 0.000100
      Altitude encoding method: Explicit elevation coordinate included with horizontal coordinates

  7. How does the data set describe geographic features?

    casovct.CASO.xLND_SurfaceEstate
    casovct.CASO.xLND_Disposals
    casovct.CASO.LND_Disposals
    casovct.CASO.LND_SurfaceEstate
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Who produced the data set?

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


  2. Who also contributed to the data set?

    BLM California State Office, Mapping Sciences
    Sacramento, CA 

  3. To whom should users address questions about the data?

    Jeff Crocker
    BLM, California State Office-Mapping Sciences
    Geographer (GIS)
    2800 Cottage Way
    Sacramento, CA 95825

    916-978-4434 (voice)
    jcrocker@ca.blm.gov
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Why was the data set created?

This data is provided for the public use.  It is intended to represent BLM administered lands in California and portions of northwestern Nevada.

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How was the data set created?

  1. Where did the data come from?

  2. What changes have been made?

    (change 1 of 4)
    Dataset copied.

    Data sources used in this process:
    • \\blm\dfs\ca\pub\gisimage\so\gis\project\sdegdbtransition\Lands\Lands.gdb

    (change 2 of 4)
    Dataset copied.

    Data sources used in this process:
    • \\blm\dfs\ca\pub\gisimage\so\gis\project\sdegdbtransition\Lands\Lands.gdb

    (change 3 of 4)
    Dataset copied.

    Data sources used in this process:
    • \\blm\dfs\ca\pub\gisimage\so\gis\project\sdegdbtransition\Lands\LandsBU.gdb

    Date: 20090521 (change 4 of 4)
    Metadata imported.

    Data sources used in this process:
    • \\blm\dfs\ca\pub\gisimage\so\gis\ca_sync\WWW\gisdownloads\metadata\landstatus.xml

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

  1. How well have the observations been checked?

    Accuracy is evaluated primarily through use of the data, and
          at the time the data is updated or otherwise edited.

  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?

    Updates emphasize BLM ownership.  Other ownership categories will
    be updated as opportunities become available.

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

    Polygons are checked to be sure all polygons have at least one set of attributes,
        and no more than one set of attributes.  Polygon edges are examined to be sure that they
        close correctly.

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How can someone get a copy of the data set?

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

Access constraints: None - Though Subject to Cost Recovery Rules
Use constraints:
These data are public information and may be used and interpreted
    by organizations, agencies, units of government, or others.  The user
    has sole responsibility for ensuring the appropriate application of
    these data and the U.S. Bureau of Land Management shall not be held
    liable for any use or misuse of the data described hereon.

    Generally, these data are intended for small scale (1:24,000 and smaller)
    natural resource management and planning applications.  It is strongly
    recommended that these data be acquired directly from the U.S. Bureau of
    Land Management and not indirectly through some other source which may
    have changed the data.  It is also strongly recommended that careful attention
    be paid to the content of the metadata file associated with these data.  Users
    are cautioned that digital enlargement of these data to scales larger than
    that at which they where originally mapped can cause misinterpretation.  Users
    are further cautioned that these data and interpretations derived from them
    do not eliminate the need for onsite survey and evaluation of specific sites
    for intensive uses.

Distributor 1 of 1

  1. Who distributes the data set?

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

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    These data are provided without the approval of the Director of the U.S.
        Bureau of Land Management and no warranty expressed or implied is made
        regarding the accuracy, completeness, or utility of these data, nor shall
        the act of distribution constitute any such warranty.  Any conclusions drawn
        from the use or misuse of these data are soley the responsibility of the user
        and the U.S Bureau of Land Management shall not be held liable for such use.
        This disclaimer applies both to individual use of these data and aggregate
        use with other data.

  4. How can I download or order the data?

  5. Is there some other way to get the data?

  6. What hardware or software do I need in order to use the data set?

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Who wrote the metadata?

Dates:
Last modified: 20090602

Metadata author:
Jeff Crocker
BLM, California State Office, Mapping Sciences
Geographer, GIS
2800 Cottage Way
Sacramento, CA 95825

916-978-4434 (voice)
jcrocker@ca.blm.gov

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

Metadata extensions used:
  • http://www.esri.com/metadata/esriprof80.html

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