BosWash
Western Massachusetts' population is concentrated in the cities and suburbs along the Connecticut River in an urban axis surrounding Springfield that is contiguous with greater Hartford, Connecticut (i.e. the Knowledge Corridor.) A secondary population concentration exists in the Housatonic-Hoosic valley due to the industrial heritage of Pittsfield and North Adams, and the development of tourism throughout that valley. This far-western zone is linked to New York City and Albany, New York more than with the rest of Massachusetts, however both populated zones are ultimately part of the Northeast megalopolis. The rest of Western Massachusetts is lightly populated, particularly the Hilltowns where densities below 50 persons per square mile (20 per km2) are the rule.