Sells, Arizona - 30x60 Minute Series Topo Map Media CD Geological Surveys

Geological Surveys

and is the first in a three part series of publications

Lace up your boots and sample twenty-eight of the finest trails at one of the world’s greatest natural wonders

which adds up to a ton of local knowledge

Sells, Arizona - 30x60 Minute Series Topo Map Media CD Geological SurveysThe distinctive characteristic of a topographic map is that the shape of the Earth's surface is shown by contour lines. Contours are imaginary lines that join points of equal elevation on the surface of the land above or below a reference surface, such as mean sea level. Contours make it possible to measure the height of mountains, depths of the ocean bottom, and steepness of slopes. A topographic map shows more than contours. The map also includes