Region | Realm
Northern America contains the majority of the Nearctic realm, spanning from southern Canada to northern Mexico and containing six subrealms as defined in the Bioregions 2023 framework—Northeast American Forests, Southeast US Savannas, Great Plains, American West, Mexican Drylands, and North Pacific Coast—containing 22 bioregions in total with a diversity of biome types. The Northeast American Forests subrealm contains four forest bioregions and includes most of the Great Lakes. The Southeast US Savannas & Forests subrealm has four bioregions and is dominated by grasslands but also includes adjoining mixed forests. The Great Plains subrealm includes three grassland bioregions stretching from southern Canada to central Texas. The American West subrealm contains five bioregions and encompasses the deserts of the Southwest and the Rocky Mountain forests. The Mexican Drylands subrealm consists of two bioregions and a diverse mix of ecoregion types across northern Mexico and the Baja Peninsula. The North Pacific Coast stretches from the border of Mexico to central Canada and includes three bioregions.