We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

EPA's website will operate in a diminished capacity on Saturday Feb 17, 2018 from 8:00 a.m. to noon EST for routine maintenance. Some services, such as search, may be temporarily unavailable for brief periods during this time. We apologize for any inconvenience.

Ecoregions of North America

North America has been divided into:

  • 15 broad, level I ecological regions;
  • 50 level II ecological regions intended to provide a more detailed description of the large ecological areas nested within the level I regions; and
  • 182 Level III ecoregions, which are smaller ecological areas nested within level II regions.

Select a link for additional details about each level, or a list of links to downloadable maps and GIS data files.