Topographic maps show changes in elevation over an area of land. Many topographic maps are prepared by the United State Geological Survey.
Many people use topographic maps such as engineers, geologist, hikers and pilots.
The landscape represented by topographic maps is interpreted by reading the contour lines. Contour lines spaced very close together represent land areas that are steep. Widely spaced contour lines represent flat land areas. Contour lines do not cross. If they did, they would indicate that two different elevations exist at the same spot.