Interpreting the colored lines, areas, and other symbols is the first step in using topographic maps. To not have symbols is to not have maps. Over time the maps became more detailed and new symbols were added for the different terrain, natural features, land boundaries, and man-made structures depicted by the surveyors. Features are shown as points, lines, or areas, depending on their size and extent. For larger buildings, the actual shapes are mapped. topographic map, called provisional, some symbols and lettering are hand- drawn. Features are shown as points, lines, or areas, depending on their size and extent. For example, individual houses may be shown as small black squares.

For larger buildings, the actual shapes are mapped. Topographic Map Legend and Symbols. U.S. Department of the Interior U.S. Geological Survey Reading Topographic Maps Interpreting the colored lines, areas, and other symbols is the fi rst step in using topographic maps. Interpreting the colored lines, areas, and other symbols is the first step in using topographic maps. topographic map, called provisional, some symbols and lettering are hand- drawn. In cartography, symbols are everything. For example, individual houses may be shown as small black squares. Topographic map symbols. In densely built-up areas, most individual buildings are omitted and an area tint is shown. U.S. Department of the Interior U.S. Geological Survey Reading Topographic Maps Interpreting the colored lines, areas, and other symbols is the fi rst step in using topographic maps. Topographic Map Keys. The very nature of a map as an abstracted representation of the Earth requires symbols to perform the abstraction. The topographic maps on TopoZone were created by the United States Geological Survey (USGS) and have evolved for more than a century.