Title supplied by cataloger based on information from sheet label. Image is a photoreduction of the mosaic created from original aerial photographs. Designating symbol BZG. Form of individual image numbering: BZG-1-[number], BZG-2-[number], BZG-3-[number], or BZG-4-[number]."Date of completion July 22, 1939" Flown by Aero Service Corp. Philidelphia, Pa. "Approximate scale, 1:20,000" [refers to individual images from which mosaic was made].Contact the Map Collection at The University of Iowa Libraries: http://www.lib.uiowa.edu/maps/contact/JPEGui:api_235engUnited States. Department of AgricultureUnited States. Agricultural Stabilization and Conservation ServicePublicButler County, Iowa, 1939, aerial photomosaic indexImageryIowa--Butler CountyIowa1930-1940University of Iowa