Castle Rock, Colorado - 30x60 Minute Series Topo Map National Audubon Society 798 scanned photographs

798 scanned photographs

forces that carry continents into collisions and then drag them apart again

200 acre-feet per year

The quadrangle includes part of the Vernon Hills along the western edge and adjoining parts of the valley floor to the east

The fifth is the black shale facies within the Hermosa Group in southeast Utah

Castle Rock, Colorado - 30x60 Minute Series Topo Map National Audubon Society 798 scanned photographsThe 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