Datasets > Polygon data > United States > 2000-2004

Omernik's Level III Ecoregions of the Continental United States, 2003

National Atlas of the United States · 2003 Full Details

Full Details

Title
Omernik's Level III Ecoregions of the Continental United States, 2003
Description
This polygon shapefile shows Omernik's Level III ecoregions, derived from a 1:7,500,000 map created by J.M. Omernik in 1987 and from refinements of Omernik's framework that were made for other projects. Ecoregions describe areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. Omernik's ecoregions are based on the premise that a hierarchy of ecological regions can be identified through the analysis of the patterns and the composition of both living and nonliving phenomena, such as geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology, that affect or reflect differences in ecosystem quality and integrity. All the characteristics are considered when determining ecoregions, but the relative importance of each characteristic may vary from one ecoregion to another. Level III is the most detailed level available nationally for this system of ecoregions. This layer is part of the 1997-2014 edition of the National Atlas of the United States., These data are intended for geographic display and analysis at the national level, and for large regional areas. The data should be displayed and analyzed at scales appropriate for 1:7,500,000-scale data. No responsibility is assumed by the National Atlas of the United States in the use of these data., None. Acknowledgment of the U.S. Environmental Protection Agency and (or) the National Atlas of the United States of America would be appreciated in products derived from these data., This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
Creator
United States. Environmental Protection Agency
Publisher
National Atlas of the United States
Subject
Ecological regions, Biotic communities, Environment, Biology and Ecology
Temporal Coverage
2003
Date Issued
2005
Rights
This item is in the public domain. There are no restrictions on use.
Rights Holder
This work is in the Public Domain, meaning that it is not subject to copyright.
Access Rights
Public
Format
Shapefile
Language
English
Date Added
October 01, 2025

Location

Cite and Reference

  • Citation
    United States. Environmental Protection Agency (2005). Omernik's Level III Ecoregions of the Continental United States, 2003. National Atlas of the United States. (dataset)
  • BTAA Geoportal Link

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