| People have been using topographical maps to | | | | Contour Lines |
| accurately navigate the earth’s terrain for many | | | | Contour lines are the most easily recognizable |
| decades now. Topographical maps are especially | | | | features of topographic maps. They are shown in |
| useful off-roads, as they provide 3D map data using | | | | brown, usually, and they connect points in the terrain |
| special symbols that indicate surface elevation. | | | | that have the same elevation. Contour lines appear at |
| Topographic mapping in the United States began in | | | | set intervals, as dictated by the contour line interval |
| 1879, when the U.S. Geological Survey sanctioned the | | | | rate shown, usually, under the scale. If the contour |
| first full topographic mapping of the entire continental | | | | interval is 20 meters, for example, it means that each |
| United States. The most common scale used for | | | | new contour line signifies a chance in elevation of 20 |
| these USGS maps was 1:24,000. USGS maps are still | | | | meters. Contour lines that are far apart signal flatter |
| used today, though new satellite and computer | | | | ground and contour lines close together signal steep |
| technology has allowed for more accurate, digital | | | | ground. |
| maps that can be used via GPS or other computer | | | | Other Features |
| handheld devices. | | | | Forests on topographic maps are symbolized by |
| How to Read Topographic Maps | | | | shaded areas of green. Great digital maps tend to |
| As mentioned, the most common scale of topographic | | | | have more up-to-date info on the location and |
| maps is 1:24,000. This means that every inch on the | | | | parameters of forests and woodland areas. Bodies of |
| map, stands for 24,000 actual inches of terrain. | | | | water, as with most maps, are shown in topographic |
| Latitude and longitude lines are the same in topographic | | | | maps in blue. Man made landmarks, like roads and |
| maps as in other maps. There is also a legend on | | | | railways are shown in red and black lines of different |
| topographic maps that illustrates how to read the | | | | designs. State, county and municipal boundaries employ |
| symbols used. All of this information can usually be | | | | black and red lines as well, but they are usually |
| found in the lower right corner of most maps. Symbols | | | | dotted or broken to avoid confusion. |
| specific to topographic maps include the following. | | | | |