Thatcher Hill, Idaho - 7.5 Minute Series Topo Map roadside geology Grand Canyon

Grand Canyon

Part of Dinosaur National Monument is in the northeast corner of the quadrangle on the Split and Blue Mountains sector of the Yampa Plateau

deadly gunfights

and because of tremendous forces deep within the earth

A national bestseller in hardcover for more than a year after its initial publication

Thatcher Hill, Idaho - 7.5 Minute Series Topo Map roadside geology Grand CanyonThe 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