Go here for data needed for this package: ftp://ftpext.usgs.gov/pub/er/wi/middleton/dblodgett/HUCAgg/
Everything can be done with the WBDHU12_30June2015.zip shapefile. It was generated from the Watershed Boundary Dataset Geo Data Base that is also included at the ftpint site above. ogr2ogr was used to make that conversion.
See function examples for usage.
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