Which feature aids in the identification of different elevations on a topographic map?

Contour lines are the primary feature that aids in the identification of different elevations on a topographic map. These lines represent areas of equal elevation above a certain reference level, usually sea level. Each contour line connects points that share the same elevation value, allowing users to visualize the terrain's shape and steepness. The spacing between these lines indicates the slope; closer lines suggest a steep slope, while lines that are spaced farther apart indicate a gentler slope. By interpreting these lines, a user can ascertain elevation changes and the overall topography of the area being mapped.

While the legend provides essential information about the symbols and markings on the map, it does not directly indicate elevation. The grid system assists with navigation and determining specific locations on the map but does not convey elevation information. Similarly, the title block contains the map's title, scale, and other administrative details but does not contribute to understanding the elevation changes represented in the topographic features themselves. Hence, the reliance on contour lines is crucial for accurately interpreting the elevation data presented on any topographic map.