This is a 30 meter grid that maps upland and wetland wildlife habitats/ecological systems for the Northeast, including all 13 states from Maine to Virginia, west to New York, Pennsylvania and West Virginia. Mapped habitat types are drawn from the Northeastern Terrestrial Habitat Classification System (NETHCS). The NETHCS is based on NatureServe’s Ecological Systems Classification, augmented with additional information from individual state wildlife classifications and other information specific to wildlife managers. A terrestrial ecological system is defined as a mosaic of plant community types that tend to co-occur within landscapes with similar ecological processes, substrates, and/or environmental gradients, in a pattern that repeats itself across landscapes. Systems occur at various scales, from "matrix" forested systems of thousands of hectares to small patch systems, such as cliffs, basin wetlands, or barrens on a particular bedrock type, of a hectare or 2.