Omernick, J. M. 19870101 Unknown n/a map Reston, Virginia, USA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ecoregion Ecoregions are based on perceived patterns of a combination of causal and integrative factors including land use, land surface form, potential natural vegetation, and soils (Omernik, 1987). This is a copy of the ecoregion coverage of Omernik (1987) with some item names modified. This is NOT the most recent version of the ecoregion definitions, which can be obtained from: Environmental Protection Agency, Western Ecology Division, Corvallis, OR at http://www.epa.gov/wed/pages/ecoregions/level_iii.htm. This coverage is intended for national-level studies of water resources. Reviews_Applied_to_Data. The ecoregions were plotted on a terminal to ensure the EXPORT file was imported properly. No claims are made regarding the accuracy of the original data or linework. 19911217 publication date Complete None planned. -127.87111726 -65.35687433 48.24430721 22.87753347 None EPA Ecoregion Map Conterminous United States inlandWaters None None U.S. Geological Survey mailing address

12201 Sunrise Valley Drive, MS 440

Reston VA 20192 USA 1-888-275-8747 h2oteam@usgs.gov Please use email. http://water.usgs.gov/GIS/browse/ecoregion_s.gif Illlustration of data set GIF dgux, 5.4R3.10, AViiON UNIX, ARC/INFO version 7.0.4 See supplemental information. See supplemental information. Omernik, J. M 1987 Annals of the Association of American Geographers 77:118-125 unknown Association of American Geographers 7500000 The coverage was installed from an ARC/INFO EXPORT file supplied by EPA Corvallis. Some item names were modified and others were redefined to make the coverage more convenient to use and to conform to more conventional item names. 19910928 Rev. 1.1 Converted to Data General workstation. Item redefinitions revised and documentation added. 19911217 Added note to metadata saying the most recent ecoregion coverage is available from EPA, Western Ecology Division. 20070125 Vector Point 3732 String 8064 GT-polygon composed of chains 3733 Albers Conical Equal Area 29.5 45.5 -96 23 0.0 0.0 coordinate pair 1.0 1.0 meters ECOREGION.PAT Polygon attribute table Omernik (1987) AREA Area of polygon in square coverage units Computed Positive real numbers n/a n/a PERIMETER Perimeter of polygon in coverage units Computed Positive real numbers n/a n/a ECOREGION# Internal feature number Computed Sequential unique positive integer n/a n/a ECOREGION-ID User-assigned feature number User-defined Integer n/a n/a ECO Full ecoregion code Omernik (1987) positive numbers are ecoregions n/a n/a PBMIN1 State code item used by EPA Omernik (1987) (FIPS) n/a n/a LWCODE Land/water code. Omernik (1987) L=land, W=water, ZZ=missing n/a n/a COLOR Working item for plotting Local numeric n/a n/a ECOREGION Ecoregion code Omernik (1987) 1-76, -1=none n/a n/a TYPICAL Indicates strength of association in ecoregion Omernik (1987) 0=most typical, 1=generally typical n/a n/a FIPSST State code Omernik (1987) (FIPS) n/a n/a Ecoregions are based on perceived patterns of a combination of causal and integrative factors including land use, land surface form, potential natural vegetation, and soils (Omernik, 1987). There are 76 ecoregions, identified by the item ECOREGION. The item TYPICAL allows a fuzzy logic whereby polygons identified with TYPICAL = 0 are "most typical" of the ecoregion they represent. Those identified by TYPICAL = 1 are "generally typical" any may not have all the characteristics. The ecoregion coverage is superimposed upon a coverage of states. The state lines may divide polygons. See overview. U.S. Geological Survey Ask USGS - Water Webserver Team mailing

507 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ecoregion Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Export Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/ecoregion.e00.gz SDTS Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/ecoregion.sdts.tgz None. This dataset is provided by USGS as a public service. 20041108 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

507 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+ecoregion FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998