Geological Survey (U.S.) Gerlach, Arch C. cartographic Maps. lcgft https://id.loc.gov/authorities/genreForms/gf2011026387 Washington, 1970. eng Six transparent overlays in envelope inserted. Signed by William T. Pecora, Under Secretary of Interior, W.A. Radlinski, Associate Director, U.S.G.S., Arch C. Gerlach, Chief Geographer, and William B. Overstreet, Chief National Atlas Project and is number 13 of 14 copies. Scales vary. Exchange; United States--Statistics--Maps. United States--Census, 1970. United States. Available also through the Library of Congress Web site as a raster image. http://hdl.loc.gov/loc.gmd/g3701gm.gct00013