Topographic Maps 101

The intricate details on a topographic map can be befuddling, even frustrating, if you are learning while out in the backcountry. But once you get familiar with the markings and symbols, reading maps will become a friendly aid, rather than a dreaded assignment. Topographic Maps Grid System Lines of latitude run parallel to the equator (east and west), and lines of longitude run perpendicular to the equator (north and south). These lines form a pattern of squares across the surface of the earth like a checker board. One square, formed by lines of longitude and latitude, measures 90 degrees x 90 degrees. Degrees are further subdivided into minutes and seconds.