Title supplied by cataloger based on information from sheet labels. Images are photoreductions of mosaics created from original aerial photographs. Designating symbol SO; form of individual image numbering: SO-15-[number], SO-16-[number], SO-17-[number], SO-18-[number], SO-19-[number], SO-20-[number], SO-21-[number], SO-22-[number], SO-23-[number], SO-25-[number], SO-28-[number], SO-31-[number], or SO-32-[number]."Date of completion 11-26-37" Flown by Gatschet Aerial Surveys, Des Moines, Iowa."Approximate scale, 1:20,000" [refers to individual images from which mosaic was made]. Library's copy 2 consists of photographic negatives (4 x 5 in.) corresponding to each of the images in its copy 1. Contact the Map Collection at The University of Iowa Libraries: http://www.lib.uiowa.edu/maps/contact/