This layer is a digital raster graphic of the 7.5 Minute USGS topographic map of the Ludlow, Massachusetts quadrangle, 1975. Scale 1:25,000. The DRG was published in 1996. 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 georeferenced to the surface of the earth and fit to the Universal Transverse Mercator (UTM) projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The source paper map was mapped, edited and published by the United States Geological Survey. The Massachusetts 7.5 minute topographic series was produced in cooperation with the Massachusetts Department of Public Works. Topography by planetable surveys 1938. Revised from aerial photographs taken 1967. Field checked 1969. 'Map photoinspected 1975. No major culture or drainage changes observed.' 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.