The political boundary datalayer is a 1:25,000 scale datalayer containing the boundaries of the 351 communities (cities and towns) in Massachusetts. The seaward boundary of coastal communities has been defined at mean high water in this datalayer. The datalayer is named TOWNS_POLY. Note that the 351 communities are the official municipal names, not including "villages" or other sections of towns. This layer includes single-part features, where offshore islands are separate features from the mainland, although the attributes are the same for all features in one municipality.

This datalayer, except the coastline, was digitized by MassGIS from a set of stable based film prints of the 1:25,000 7.5' quadrangles purchased from the USGS by the Massachusetts Dept. of Public Works. The coastline was taken from the USGS 1:100,000 hydrography DLG database. It was selected visually and appended to the digitized town boundaries.