Title supplied by cataloger based on information from sheet labels. Images are photoreductions of mosaics created from original aerial photographs. Designating symbol DF form of individual image numbering: DF-1-[number], DF-2-[number], DF-3-[number], or DF-4-[number]. Date of publication inferred from dates on individual photographs within the mosaic. Flown by Aerial Explorations, Inc. New York, N.Y. "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/