MassGIS 2003 Massachusetts Hydrography (1:25,000) (Arcs) (March 2003)

MassGIS has edited and modified the USGS 1:25,000 Hydrography Digital Line Graph (DLG) quadrangle files and the USGS 1:100,000 Hydrography DLG files and digitized hydrographic features from the USGS 1:25,000 Topographic Quadrangles to produce a hybrid 1:25,000 Massachusetts Hydrography Datalayer.

The 1:100,000 DLG features were enhanced by digitizing those streams and ponds from the USGS quadrangles that were not part of the 1:100,000 data. MassGIS has also scanned USGS mylar separates to begin replacing the 1:100,000 enhanced data with 1:25,000 features.