Title supplied by cataloger based on information from sheet labels. Images are photoreductions of mosaics created from original aerial photographs. Designating symbol BKP; form of individual image numbering: BKP-1-[number], BKP-2-[number], BKP-3-[number], BKP-4-[number], BKP-5-[number], BKP-6-[number], or BKP-7-[number]. Survey began in 1938."Date of completion Feb 4, 1939" Flown by Iowa 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/