Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000Ecoregions by state were extracted from the seamless national shapefile. Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. They are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components. These general purpose regions are critical for structuring and implementing ecosystem management strategies across federal agencies, state agencies, and nongovernment organizations that are responsible for different types of resources within the same geographical areas. The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of patterns of biotic and abiotic phenomena, including geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology. The relative importance of each characteristic varies from one ecological region to another. A Roman numeral hierarchical scheme has been adopted for different levels for ecological regions. Level I is the coarsest level, dividing North America into 15 ecological regions. Level II divides the continent into 52 regions (Commission for Environmental Cooperation Working Group, 1997). At Level III, the continental United States contains 104 regions whereas the conterminous United States has 84 (U.S. Environmental Protection Agency, 2005). Level IV ecoregions are further subdivisions of Level III ecoregions. Methods used to define the ecoregions are explained in Omernik (1995, 2004), Omernik and others (2000), and Gallant and others (1989). Literature cited: Commission for Environmental Cooperation Working Group, 1997, Ecological regions of North America- toward a common perspective: Montreal, Commission for Environmental Cooperation, 71 p. Gallant, A. L., Whittier, T.R., Larsen, D.P., Omernik, J.M., and Hughes, R.M., 1989, Regionalization as a tool for managing environmental resources: Corvallis, Oregon, U.S. Environmental Protection Agency, EPA/600/3-89/060, 152p. Omernik, J.M., 1995, Ecoregions - a framework for environmental management, in Davis, W.S. and Simon, T.P., eds., Biological assessment and criteria-tools for water resource planning and decision making: Boca Raton, Florida, Lewis Publishers, p.49-62. Omernik, J.M., Chapman, S.S., Lillie, R.A., and Dumke, R.T., 2000, Ecoregions of Wisconsin: Transactions of the Wisconsin Academy of Science, Arts, and Letters, v. 88, p. 77-103. Omernik, J.M., 2004, Perspectives on the nature and definitions of ecological regions: Environmental Management, v. 34, Supplement 1, p. s27-s38. Comments and questions regarding Ecoregions should be addressed to Glenn Griffith, USGS, c/o US EPA., 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4465, email:griffith.glenn@epa.gov Alternate: James Omernik, USGS, c/o US EPA, 200 SW 35th Street, Corvallis, OR 97333, (541)-754-4458, email:omernik.james@epa.govEcoregion maps assist managers of aquatic and terrestrial resources to understand the regional patterns of the realistically attainable quality of these resourcesElectronic versions of ecoregion maps and posters, as well as other ecoregion resources are available at: http://www.epa.gov/wed/pages/ecoregions.htm. Symbology layers for US Levels III and IV also available. Level IV ecoregions for California, Arizona and New Jersey are considered draft versions, as of December, 2011. Ecoregions were digitized at 1:250,000 scale and are intended for large geographic extents (i.e. states, multiple counties, or river basins). Use for smaller areas, such as individual counties or a 1:24,000 scale map boundary, is not recommended.vector digital dataU.S. Environmental Protection AgencyU.S. EPA Office of Research & Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL) Corvallis, ORFIPS Pub 199No ConfidentialityStandard Technical ControlsU.S. Environmental Protection Agency, Office of Research & Development (ORD) - National Health and Environmental Effects Research Laboratory (NHEERL)Marc WeberGIS Analystmailing and physical address

200 S.W. 35th St.

CorvallisOR97333(541) 754-4469weber.marc@epa.govhttp://www.epa.gov/Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcGIS 10.0.0.2414nml4eco-110.022491-102.54795837.49816631.2392561-125.012651-113.80359543.45505931.4318291002FGDC Content Standards for Digital Geospatial MetadataFGDC-STD-001-1998local time2011031020140920SRA / Raytheon Contractors to US EPAColleen Burch JohnsonGIS Analystmailing and physical address

200 S.W. 35th St

CorvallisOR97333(541) 754-4454johnson.colleen@epa.govhttp://www.epa.gov/ISO 19115 Geographic Information - MetadataDIS_ESRI1.0dataset002file://\\DC2626XMWEBER\E$\Ecoregions\Updated_Ecoregions\Final_Data\By_State\Level3\az.shpLocal Area Network2.291ShapefileShapefile4.72420120103The state borders were derived from the dtl_st.sdc on the ArcGIS DVD provided by ESRI. It was modified by removing Alaska and Hawaii polygons and all but the State field, adding some coastal islands based on imagery or NHDPlus areas, and restoring topology (removing internal gaps and small overlaps). The EPA regions were added to this custom geodatabase (dtl_48plyf) prior to the intersection process with the seamless ecoregion data.201005261) U.S.G.S. 1:250,000 topographic maps are used to delineate the ecoregions. The lines drawn are manually digitized or scanned to produce georeferenced electronic files. 2) All base maps are joined together and errors along the edges are resolved. 3) Topology is established and the maps are reviewed for accuracy, completeness, and conformity with the original lines. Corrections are made as needed and topology regenerated. 4) Attributes are added. 5) Maps are plotted for visual inspection by two individuals and necessary changes made. 6) Ecoregions from all available states are merged and dissolved to identify and correct inconsistencies. 7) Polygons of the corrected seamless ecoregion features are extended beyond the coastal borders. 8) State and Ecoregion datasets are intersected. 9) Topology errors removed. 10) Final QAAlthough ecoregion polygons and attributes have been checked for accuracy, some errors may remain. Polygons along state borders were reviewed and updated, May 2010.Level IV ecoregions are draft versions for Arizona, California, and New Jersey as of December, 2011. Ecoregions were digitized at 1:250,000 scale and are intended for large geographic extents (i.e. states, multiple counties, or river basins). Use for smaller areas, such as individual counties or a 1:24,000 scale map boundary, is not recommended.Data were collected using methods that have unknown accuracy (EPA National Geospatial Data Policy [NGDP] Accuracy Tier 10). For more information, please see EPA's NGDP at http://epa.gov/geospatial/policies.html)VectorG-polygon101coordinate pairmeters0.0000010.000001Albers Conical Equal Area29.50000045.500000-96.00000023.0000000.0000000.000000North American Datum of 1983Geodetic Reference System 806378137.000000298.257222USA_Contiguous_Albers_Equal_Area_Conic_USGS_version81nm_eco_l4FIDInternal feature number.ESRISequential unique whole numbers that are automatically generated.ShapeFeature geometry.ESRICoordinates defining the features.OBJECTIDInternal feature number.Sequential unique whole numbers that are automatically generated.US_L4CODECode for Level IV Ecoregion (US)USEPAUS_L4NAMEName for Level IV Ecoregion (US)USEPAUS_L3CODECode for Level III Ecoregion (US)USEPAUS_L3NAMEName for Level III Ecoregion (US)USEPANA_L3CODECode for Level III Ecoregion (North America)CECNA_L3NAMEName for Level III Ecoregion (North America)CECNA_L2CODECode for Level II Ecoregion (North America)CECNA_L2NAMEName for Level II Ecoregion (North America)CECNA_L1CODECode for Level I Ecoregion (North America)CECNA_L1NAMEName for Level I Ecoregion (North America)CECSTATE_NAMEName of State (US)EPA_REGIONEPA Administrative RegionShape_LengLength of feature in internal unitsESRI Positive real numbers that are automatically generated.Shape_AreaArea of feature in internal units squared.ESRI Positive real numbers that are automatically generated.Positive real numbers that are automatically generated.L4_KEYUS Level IV Code and Name for Legend, Match to StyleL3_KEYUS Level III Code and Name for Legend, Match to StyleL2_KEYNA Level II Code and Name for Legend, Match to StyleL1_KEYNA Level I Code and Name for Legend, Match to Style