Title supplied by cataloger based on information from sheet labels. Images are photoreductions of mosaics created from original aerial photographs. Designating symbol TF; form of individual image numbering: TF-8-[number], TF-9-[number], TF-10-[number], TF-12-[number], or TF-13-[number]. "Date of completion 08-05-37". 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/