 New York lies upon the portion of the Appalachian Mountains where the mountains generally assume the character of hills and finally sink to a level of the lowlands that surround the great depression filled by Lake Ontario and the St. Lawrence River.Three distinct mountain masses can be identified in the state.The most easterly of these ranges—a continuation of the Blue Ridge Mountains of Virginia—enters the state from New Jersey and extends northeast through Rockland and Orange counties to the Hudson River, continuing on the east side of that river as the highlands of Putnam and Dutchess counties.