Description: In Massachusetts, cities and towns are recognized and recorded as “county subdivisions” by the Census Bureau. County subdivisions are the primary divisions of counties and their equivalent entities for the reporting of decennial census data. A 5-character FIPS code (recorded in COUSUBFP) is used to uniquely identify each county subdivision. Census towns have linework that is often identical to the linework found in MassGIS' municipality boundaries, but also contains many minor discrepancies, particularly along hydrologic and coastal features. The annual Boundary and Annexation Survey (BAS) program attempts to reconcile significant differences in linework (typically discrepancies of 30 feet or more) between Census county subdivisions and the authoritative record, especially where populations are involved. Census towns have been processed and made available to provide a city and town reference for mapping that should align better than the MassGIS municipality boundaries with other Census-derived geographies, including voting districts. Some of the attributes from the MassGIS municipality boundaries have been transcribed into the Census towns attributes.Town population counts from 1970 to 2010 were obtained from the “City and Town Sortable Rankings” tables provided by the UMass Amherst Donahue Institute on this Secretary of the Commonwealth’s website. 1960 town population counts were obtained and transcribed from this report published on this state library archives webpage by the Massachusetts Department of Commerce and Development, Bureau of Research and Statistics.In February 2026, MassGIS edited the GEOID20 values, names in NAMELSAD20, and 5-digit values in COUSUBFP20 for 4 municipalities (Amesbury, Easthampton, Methuen and Watertown) to reflect latest updates by the U.S. Census Bureau. Any analysis involving these communities that attempts to use ACS or other Census product data published prior to 2024 will require the user to manually change the GEOID20 value to be the old GEOID value listed here to facilitate linkage:Amesbury - OLD GEOID20/Name: 2500901260/Amesbury Town city. NEW GEOID20/Name: 2500901185/Amesbury cityEasthampton - OLD GEOID20/Name: 2501519370/Easthampton Town city. NEW GEOID20/Name: 2501519365/Easthampton cityMethuen - OLD GEOID20/Name: 2500940710/Methuen Town city. NEW GEOID20/Name: 2500940675/Methuen cityWatertown - OLD GEOID20/Name: 2501773440/Watertown Town city. NEW GEOID20/Name: 2501773405/Watertown city
Copyright Text: US Census Bureau 2020 TIGER/Line data from MAF/TIGER database (MTDB).
Massachusetts Bureau of Geographic Information (MassGIS), Executive Office of Technology Services and Security (EOTSS)
Description: This dataset consists of 2-dimensional roof outlines ("roofprints") for all buildings larger than 150 square feet, as initially interpreted by a contractor (Rolta) for the whole area of the Commonwealth using DigitalGlobe ortho images obtained in 2011 and 2012, supplemented with LiDAR (Light Detection And Ranging) data collected from 2002 to 2011 for the eastern half of the state.The roofprints as delivered by Rolta were enhanced by MassGIS using Normalized Digital Surface Models (NDSMs) derived from the same LiDAR data. Other layers were used, including the Standardized Parcels, to aid in review, especially where LiDAR data were not available.In 2019, MassGIS refreshed the data to a baseline of 2016 and continues to update features using newer aerial imagery that allows MassGIS staff to remove, modify and add structures to keep up with more current ground conditions. Structures from the original compilation that are removed are stored in an "archive" feature class for edit tracking and historical purposes. Also in 2019, MassGIS replaced the polygons in Boston with data from the city. In March 2021, the layer was updated with 2017 and 2018 structure review edits along with the first data edits compiled atop spring 2019 imagery. Updates based on 2019 imagery were completed in July 2021. Updates based on 2019 imagery were completed in August 2022. Updates based on 2021 imagery were completed in October 2023. Updates based on 2023 imagery were completed in August 2024. MassGIS made additional edits from December 2025 to May 2026 based on spring 2025 imagery, with assistance from Blackshark AI object detection tools.Last updated on 5/20/2026.The layer is named STRUCTURES_POLY. It is updated periodically from STRUCTURES_POLY_V, which is registered as versioned for editing.
Description: This dataset consists of 2-dimensional roof outlines ("roofprints") for all buildings larger than 150 square feet, as initially interpreted by a contractor (Rolta) for the whole area of the Commonwealth using DigitalGlobe ortho images obtained in 2011 and 2012, supplemented with LiDAR (Light Detection And Ranging) data collected from 2002 to 2011 for the eastern half of the state.The roofprints as delivered by Rolta were enhanced by MassGIS using Normalized Digital Surface Models (NDSMs) derived from the same LiDAR data. Other layers were used, including the Standardized Parcels, to aid in review, especially where LiDAR data were not available.In 2019, MassGIS refreshed the data to a baseline of 2016 and continues to update features using newer aerial imagery that allows MassGIS staff to remove, modify and add structures to keep up with more current ground conditions. Structures from the original compilation that are removed are stored in an "archive" feature class for edit tracking and historical purposes. Also in 2019, MassGIS replaced the polygons in Boston with data from the city. In March 2021, the layer was updated with 2017 and 2018 structure review edits along with the first data edits compiled atop spring 2019 imagery. Updates based on 2019 imagery were completed in July 2021. Updates based on 2019 imagery were completed in August 2022. Updates based on 2021 imagery were completed in October 2023. Updates based on 2023 imagery were completed in August 2024. MassGIS made additional edits from December 2025 to May 2026 based on spring 2025 imagery, with assistance from Blackshark AI object detection tools.Last updated on 5/20/2026.The layer is named STRUCTURES_POLY. It is updated periodically from STRUCTURES_POLY_V, which is registered as versioned for editing.
Description: This dataset consists of 2-dimensional roof outlines ("roofprints") for all buildings larger than 150 square feet, as initially interpreted by a contractor (Rolta) for the whole area of the Commonwealth using DigitalGlobe ortho images obtained in 2011 and 2012, supplemented with LiDAR (Light Detection And Ranging) data collected from 2002 to 2011 for the eastern half of the state.The roofprints as delivered by Rolta were enhanced by MassGIS using Normalized Digital Surface Models (NDSMs) derived from the same LiDAR data. Other layers were used, including the Standardized Parcels, to aid in review, especially where LiDAR data were not available.In 2019, MassGIS refreshed the data to a baseline of 2016 and continues to update features using newer aerial imagery that allows MassGIS staff to remove, modify and add structures to keep up with more current ground conditions. Structures from the original compilation that are removed are stored in an "archive" feature class for edit tracking and historical purposes. Also in 2019, MassGIS replaced the polygons in Boston with data from the city. In March 2021, the layer was updated with 2017 and 2018 structure review edits along with the first data edits compiled atop spring 2019 imagery. Updates based on 2019 imagery were completed in July 2021. Updates based on 2019 imagery were completed in August 2022. Updates based on 2021 imagery were completed in October 2023. Updates based on 2023 imagery were completed in August 2024. MassGIS made additional edits from December 2025 to May 2026 based on spring 2025 imagery, with assistance from Blackshark AI object detection tools.Last updated on 5/20/2026.The layer is named STRUCTURES_POLY. It is updated periodically from STRUCTURES_POLY_V, which is registered as versioned for editing.