Before revision: DLGs are distributed at three different scales: large-scale, which normally correspond to the USGS 7.5- by 7.5-minute, 1:24,000 and 1:25,000-scale topographic quadrangle map series and 1:63, 3360-scale for Alaska ; intermediate scale, which are derived from the USGS 30- by 60-minute, 1:100,000-scale map series; and small-scale, which are derived from the USGS 1:2,000,000-scale sectional maps of the National Atlas of the United States.
After revision: DLGs are distributed at three different scales: large-scale, which normally correspond to the USGS 7.5- by 7.5-minute, 1:24,000 , 1:25,000-scale topographic quadrangle map series and 1:63, 360-scale for Alaska and 1:30,000-scale for Puerto Rico ; intermediate scale, which are derived from the USGS 30- by 60-minute, 1:100,000-scale map series; and small-scale, which are derived from the USGS 1:2,000,000-scale sectional maps of the National Atlas of the United States.