This layer is a digital raster graphic of the historic 15-minute USGS topographic map of the Greylock, Massachusetts quadrangle. The survey date (ground condition) of the original paper map is 1885, the edition date is November, 1898 and it was reprinted in July, 1901.
A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map.
The names of quadrangles which border this one appear on the map collar in their respective positions (N,S,E,W) in relation to this map.