Lysite, Wyoming - 30x60 Minute USGS Topographic Map Birds The oversize baseplate is ideal

The oversize baseplate is ideal for accurate triangulation

Over the past decade

The Rock and Gem Book is the perfect encyclopedia for young geologists to consult

The high Wind River Mountains of Wyoming give birth to the Green

Professional photos: Crisp

Lysite, Wyoming - 30x60 Minute USGS Topographic Map Birds The oversize baseplate is idealThe 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