The terrain is represented by bands of elevation, spot elevations, and major drainage features. The elevation guide provides the map reader with a means of rapid recognition of major landforms. In recent edition maps, there is a note indicating the conversion of azimuths from grid to magnetic and from magnetic to grid next to the declination diagram. These are located in the center of the lower margin. They are rulers used to convert map distance to ground distance.
Maps have three or more bar scales, each in a different unit of measure.
Care should be exercised when using the scales, especially in the selection of the unit of measure that is needed. This note is found in the center of the lower margin normally below the bar scales. It states the vertical distance between adjacent contour lines of the map. When supplementary contours are used, the interval is indicated. In recent edition maps, the contour interval is given in meters instead of feet.