Madras, Oregon - 30x60 Minute Series Topo Map american southwest First published in 1910

First published in 1910

The guides also promote the popular Junior Ranger programming found throughout the National Parks system

highlighting examples of fundamental features

and migratory bird refuges

Muddy Mountain Wilderness

Madras, Oregon - 30x60 Minute Series Topo Map american southwest First published in 1910The 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