Topographic maps help travelers identify terrain and points of interest.
A topographic map shows geological details of a particular region, with contour lines and symbols that represent slopes, mines, vegetation, mud, sand and gravel formations. Both natural and man-made land features are represented on a topographic map. The USGS (United States Geological Survey) produces topographical maps, which are used by campers, hikers, scientists and students to identify regions they are visiting or exploring in detail.
Contour Lines
These lines indicate land with the same elevation. They are represented by a dark color (usually black or brown) and include a number indicating elevation of the land in feet. Closely-spaced contour lines show deep slopes, while lines that are far apart indicate gentle slopes.
Vegetation
A light green box indicates trees that are 6 feet tall or higher. Uneven, light green dots represent low-hanging bushes or brush. Formally planted vegetation, like an orchard, is represented by evenly placed, light green dots. A light green pattern, similar to that of an ink stamp, indicates vineyards.
Land Surfaces
Faint brown dots on a topographic map show the location of dunes, sand or mud. Unevenly spaced brown dots of varying hues show moraines (rocks and sand deposited by a glacier) or gravelly areas. An intricate land formation with irregular features (a lava bed, for example) may be shown with a grayish-brown box or series of short, wavy brown lines. Short, thick brown lines designate a tailings pond (debris from mill or factory waste).
Mines and Caves
Two crossed pick axes indicate a quarry or working mine. Two crossed arrows pointing downward specify a clay or sand pit. A "Y" lying on its side indicates the entrance to a cave or mine tunnel. An "X" or half-black, half-white box represents a mine shaft. Brown lines of varying lengths arranged in an oval shape show the location of a mine dump.
Buildings and Man-Made Structures
A black rectangular box, small white square, cross-hatched rectangle (or one with angled lines) indicate a general building. A black square with a pennant flag on top represents a school. A black box with a cross on top is a church. A solid pink or grayish-brown rectangle indicates a large residential or built-up area. A black or white cross lying on its side indicates an airport.
Highways and Roads
A thick red line indicates an interstate or primary highway. A red and white line indicates a hard surface secondary highway, like a state or county route. Two thick black lines with a thin one in the middle represent a dual highway with traffic lanes going in opposite directions. A thick red line over a light blue rectangle indicates a bridge
Railroads
Thick black lines with short lines through them designate railroad tracks. A single thick black line represents one track, two thick black lines indicate two tracks, and so forth.
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