DATABASE NAME

     NPS:  National Park Boundaries

DATABASE DESCRIPTION

     Variable scale boundaries for selected National Parks,
     Recreation Areas, Seashores, Military Parks, Historical
     Areas, and Monuments in the United States

ORIGINATING AGENCY

     National Park Service

AGENCY RESPONSIBLE FOR MAINTAINING DATA

     Bureau of Transportation Statistics

CONTACT

     National Transportation Atlas Databases
     Bureau of Transportation Statistics
     U.S. Department of Transportation
     Washington, DC  20590
     (202) 366-DATA
     Internet:  info@bts.gov

SOURCE

     Variable (see DISCUSSION)

ACCURACY

     Variable (see DISCUSSION)

TYPE OF GIS DATABASE

     Area database with polygons and links

FILES/SIZE/NUMBER OF RECORDS

     Two ASCII files

     1)   nps.ply        polygon file contains area attributes
     2)   nps.lin        link file contains link attributes,
                         locations, and shapes

     Approximate size of files:    4,322,000 bytes
     Approximate number of areas:  880 polygons make up
                                   approximately 350 parks
     Approximate number of links:  2200

FILE STRUCTURE

     The files are ASCII-comma delimited.  Character fields are
     enclosed in quotation marks.  Each file has a header record
     at the beginning of the file which lists the ITEMs of each
     record.

     The Polygon File

   FIELD  ITEM                TYPE      REMARKS

     1    ID                  Num       Unique Identification
                                        number
     2    SB                  Num       Always 0
     3    ABRV                Char      The NPS four letter
                                        abbreviation for each
                                        park service unit.
     4    LONGITUDE           FLoat     Longitude, in decimal
                                        degrees, of property
                                        centroid-explicit decimal
     5    LATITUDE            Float     Latitude, in decimal
                                        degrees, of property
                                        centroid-explicit decimal
     6    SQ KM               Float     Area of property in
                                        square kilometers
     7    PAREA               Float     The total acreage as
                                        listed in the NPS park
                                        handbook (1991).
     8    CLASS               Num       The Clean Air Act level
                                        of air quality
                                        protection.  This can be
                                        class one or two with
                                        class one having the
                                        highest protection under
                                        the law.
     9    SNR                 Num       This can be a zero or a
                                        one with a one indicating
                                        that this park is a
                                        Significant Natural
                                        Resource and part of the
                                        I & M initiative.
     10   PNAME               Char      The full park name with
                                        the park type designation
                                        abbreviated.
     11   REGION              Char      This is the name of the
                                        NPS region that is
                                        responsible for each
                                        park.  This is subject to
                                        change in the future with
                                        the reorganization of the
                                        NPS.
     12   GEOG                Char      This is a field
                                        indicating the area of
                                        the world in which the
                                        park is located.  The
                                        data will be USA, ALAS,
                                        HAW, GUAM, AMSO, and
                                        VIRG.  Any park with
                                        "ALAS" in the GEOG item
                                        is informing the user
                                        that the Alaska
                                        Projection would best be
                                        used to draw the map. 
                                        AMSO represents American
                                        Samoa. VIRG represents
                                        the Virgin Islands.
     13   LABEL               Char      This field can be a one
                                        or a two with a "1"
                                        representing the main
                                        polygon for the park. 
                                        Any polygon with a "2"
                                        represents additional
                                        areas associated with a
                                        single NPS unit. This
                                        field is mainly useful 
                                        for selecting each park
                                        only once as there is a
                                        record for every polygon. 
                                        Many parks have more than
                                        one polygon.
     14   STFIPS              Num       The state FIPS code that
                                        the park is primarily
                                        identified with.
     15   STATE               Char      The state that the park
                                        is primarily identified
                                        with. 
     16   SCALE               Char      This is the best known
                                        scale at which this
                                        boundary was digitized
                                        from. A scale of "1:0"
                                        means unknown scale.
     17   DATE                Num       This is the year of the
                                        map from which the
                                        boundary was digitized. 
                                        Some boundaries came from
                                        more than one map at more
                                        than one scale and date.
     18   SOURCE              Char      This is the source map
                                        from which the boundary
                                        was digitized.

     The Link File

   FIELD  ITEM                TYPE      REMARKS

     1    ID                  Num       Unique identification
                                        number
     2    Polyleft            Num       Polygon Id to the left
                                        side of the line
     3    Polyright           Num       Polygon Id to the right
                                        side of the line
     4    Left Park           Num       Park ID on left side of
                                        line
     5    SBleft              Num       Always 0
     6    Right Park          Num       Park ID on right side of
                                        line
     7    SBright             Num       Always 0
     3    N                   Num       Number of following
                                        Longitude-Latitude pairs
                                        in decimal degrees
     4    Longitude 1st pair  Float     Explicit decimal}
     5    Latitude 1st pair   Float     Explicit decimal} 

     Long.-Lat. pairs         Float     Shape points of the link
     repeat N-2 times         Float     in pairs of long.-lat.

     Longitude last pair      Float     Explicit decimal}
     Latitude last pair       Float     Explicit decimal}


DISCUSSION

     This Park Boundaries file is the result of an immediate need
     for this type of data in several GIS databases being setup
     in the National Park Service.  These digital boundaries
     represent the "best guess" and data that could be collected
     in a short time.

     This data is not an "official" distribution by the National
     Park Service, but is only provided to assist those persons
     who require something to  work with.

     The data presented here is from an Arc/Info (version 6.1.1) 
     export file which contains a polygon coverage in double
     precision using the Albers Equal Area Projection for the
     Continental US.  Only 348 parks out of the current 368 are
     represented in this data set.  Although every attempt has
     been made to find errors and correct them it is still
     probable that some still exist. The boundaries are not
     necessarily the most up to date and the acreages and other
     attributes may be incorrect.

     Remember, this coverage has been assembled from many other
     existing databases and any errors digitized or keyed in at
     those sites may still exist in this composite.  The
     individual boundaries were collected when possible from
     Parks that maintain their own GIS databases, digitized from
     existing 1:24000 scale USGS quadrangles, and various other
     maps ranging in scale from 1:360 to 1:2,000,000.  The dates
     from these sources range from 1965 to the present and do not
     necessarily reflect all boundary changes that have occurred
     during this time period.

     Of the original 348 parks represented, 23 of them are shown
     with 2 meter square boxes.  Good digitized boundaries for
     these parks have not been located yet but, we do have a
     point location within them.  The boxes were used to keep
     this coverage a strictly polygon coverage instead of mixing
     points in with it.  

     The coverage is based on the Albers Equal Area projection
     for the continental US and uses the USGS's coordinate system
     for the 1:2,000,000 National Atlas.  The Arc/Info "describe"
     command will detail the projection.  Those park service
     units that are outside the continental US are not shown well
     in this projection, but it was simpler to maintain a single
     coverage of all parks.  Those parks with a "calculated" area
     of only 4 meters are the point locations referred to above.  
     