 Recent USGS digital "National Map" omits several important geographic details that were featured in the original USGS topographic map series (1945-1992).Examples of omitted details and features include power transmission lines, telephone lines, railroads, recreational trails, pipelines, survey marks, and buildings.For many of these feature classes, the USGS is working with other agencies to develop data or adapt existing data on missing details that will be included in The National Map.