From 1945 to 1992 the United States Geological Survey published tens of thousands of 1:24,000 scale topographic maps. The maps are a feat, decades of work by hundreds of skilled cartographers, surveyors, geodesists, photogrammetrists and drafters.

These maps, 42 of which are tiled here, divide the country into 70-square-mile rectangles. A U.S.G.S. guy (tie?) inspected every inch of a stereographic (think blue-and-red 3D glasses) aerial photo, logging what the U.S.G.S wanted to locate: buildings of temporal or spiritual authority, roads, petrochemical and electrical infrastructure, survey benchmarks, water treatment plants, high and low points, rivers, streamgages, bridges, railroads, cliffs, reefs, soundings, piers, prisons, lakes, swamps, and even isolines of equal elevation: the topography.