The ecoregion is bounded on the east by the Atlantic Ocean. To the north, it transitions to the New England-Acadian forests, which cover most of northern and inland New England. To the west, the ecoregion transitions to Allegheny Highlands forests and the Appalachian-Blue Ridge forests of the Appalachian Mountains. To the south lie the Southeastern mixed forests and the Middle Atlantic coastal forests. The ecoregion surrounds the distinct Atlantic coastal pine barrens ecoregion, which covers portions of New Jersey, Long Island and Cape Cod in southeastern Massachusetts.