DLG

DLG- Digital Line Graph. These images are georeferenced, raster formatted, and contain digital vector data, in that map features are stored as lines (arcs), points, and areas (polygons). DLGs are derived from hypsographic data (contour lines) using USGS 7.5-minute, 15-minute, 2-arc-second (30- by 60-minute), and 1:2 million-scale topographic quadrangle maps. The 7.5- and 15-minute DLGs are within the large-scale category; the 2-arc-second DLGs are within the intermediate-scale category, and the 1:2 million-scale DLGs are within the small-scale category. From this DLG of San Francisquito Creek and the surrounding area, features such as waterway networks (hydrography), topography, road networks, boundaries, and utility lines can be seen (http://geography.wr.usgs.gov/sfcreek/dlg.html).