Devils Tower, Wyoming - 30x60 Minute USGS Topographic Map Estwing with an other-worldly terrain of

with an other-worldly terrain of red rocks and ancient lava flows

The current edition

Special sections on coalbed methane and low-BTU gases

and Jacqueline E

Devils Tower, Wyoming - 30x60 Minute USGS Topographic Map Estwing with an other-worldly terrain ofThe 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