Halls Crossing, Utah - 7.5 Minute Series Topo Map Book comprehensive field guide--brimming with concise

comprehensive field guide--brimming with concise descriptions and stunning color photographs

Parry provides detailed commentary on historical exploration

700-mile Alaska-Yukon Expedition

surficial and bedrock geologic mapping

and areas of critical environmental concern

Halls Crossing, Utah - 7.5 Minute Series Topo Map Book comprehensive field guide--brimming with conciseThe 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