Contour lines on a topographic map are imaginary lines connecting points on the map that have the same elevation on the surface of the land above or below mean sea level. These found abstractions taken from the US Geological Survey's 7½ Minute Series reveal natural and man-made shapes and patterns of each landscape at the time each map was drawn. I begin in the top left corner with black and alternate black and white, filling in the space between the contour lines, until I reach the lower right corner. The titles are taken directly from the maps themselves.