20200928 17464700 1.0 TRUE TRUE ustOverlay The collection of topoView related services highlight the topographic maps scanned for the USGS’s Historical Topographic Map Collection (HTMC). The goal of this scanning, which started in 2011, is to provide a digital repository of USGS 1:250,000 scale and larger (more detailed) maps printed between 1884 (the inception of the topographic mapping program), and 2006. Currently, there are more than 178,000 maps in the HTMC. For additional information on topoView and the HTMC, go to http://ngmdb.usgs.gov/maps/topoview/. USGS topoview national historical topographic map database topo history topo maps ngmdb national map TopoView related services were created by the NGMDB, in support of topographic mapping program managed by the NGP. U.S. Geological Survey iVBORw0KGgoAAAANSUhEUgAAASwAAADICAYAAABS39xVAAAAAXNSR0IB2cksfwAAAAlwSFlzAAAO xAAADsQBlSsOGwAAAqpJREFUeJzt1DENADAMwLAd5U+5o7BvimQjyJXZ3T0AAfM7AOCVYQEZhgVk GBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFY QIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZ hgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgW kGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECG YQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYF ZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBh WECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEB GYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQY FpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhA hmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmG BWQYFpBhWECGYQEZhgVkGBaQYVhAhmEBGYYFZBgWkGFYQIZhARmGBWQYFpBhWECGYQEZhgVkGBaQ YVhAhmEBGYYFnIoLreIHHblfYqUAAAAASUVORK5CYII=