Level III Ecoregions

Ecoregions were developed by J.M. Omernik in 1987 and are identified by analyzing the patterns and composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity. These phenomena include geology, landforms, soils, vegetation, climate, land use, wildlife, and hydrology. On the map, darker tones of the same class represent more typical characteristics of the ecoregion.

Hover over an ecoregion below for a full description from USEPA.

Subbasin Maps


GIS Dataset Title Level III Ecoregions, Susquehanna River Basin
Dataset Description Polygon dataset that depicts level III ecoregions for the Susquehanna River Basin. 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).
Date 2006
Scale 1:7,500,000
Agency USGS; J. M. Omernik
Download GIS Dataset PASDA - Ecoregions (Level 3)
Metadata Ecoregions (Level 3), 2006