Altoona Pennsylvania,home of the central yard of the Pennsylvania Railroad in Green and Tan topographic dsetail with an overlay in red to show new roadways, a new competitor to the railroad. 16 x 21" Copper Engraved Topographic map , created by the US Geological Survey in 1/62,500 scale. Aka: 15 Minute Sheet sectioning the United States in conjunction with the Township and Range Grad established by the US Coast Survey through earlier surveys. This series is the first in depth mapping of the nation , done by 6 man survey teams walking the nation with the tools of the surveying trade to document the topography, geology, areal geology, structural geology and economic geology of the United States. 20' ft. contour lines in sepia define the real human scale of the maps, geologies in color assist in visualizing the complex conceptual content . Containing state of the art printing and data content produced and updated through the 20th century and used as baseline for all economic and environmental exploitation , as intended by design. Inclusive of riparian information, roads, trails and all existing structures. Technical obsolescence and Library De-accesssion has made these once common maps both rare and desirable , with availability in the open market uncommon with other dealers. Produced in great numbers and readily available these were the hiking, biking, fishing and building maps essential then and so helpful today to trace historical information. Current GPS data is based in part on this analog hand made map. Fine Condition