A county shapefile was generated from the USGS DLG CD-ROM and reprojected into a NAD83 dataset.
The counties in the shapefile were split as appropriate to create Public Forecast Zones and all
county boundaries were retained. This shapefile is retained as an offline private shape file called
a "master" file and it contains unique polygons of county, cwa and forecast zone data.
All changes to counties, zones, CWAs are first made to this "master" file.
To create the counties data set, a copy of the master file is created and renamed and the polygons are
"dissolved" on the FIPS code field and the lat/lon of the centroids are calculated.