1:2,000,000-scale Hydrologic Units of the United States (OLDER)

This data set has been superseded by huc2m.
This file contains hydrologic unit boundaries and codes for the conterminous
United States along with Alaska, Hawaii, Puerto Rico and the U.S. Virgin Islands.
It was revised for inclusion in the National Atlas of the United States of America,
and updated to match the streams file created by the USGS National Mapping
Division (NMD) for the National Atlas of the United States of America.
For the most current data and information relating to
hydrologic unit codes (HUCs) please see
http://water.usgs.gov/GIS/huc.html. The Watershed
Boundary Dataset (WBD) is the most current data
available for watershed delineation. See
http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/water/watersheds/dataset