Title supplied by cataloger based on information from sheet labels. Images are photoreductions of mosaics created from original aerial photographs. Designating symbol BKN; form of individual image numbering: BKN-1-[number], BKN-2-[number], BKN-3-[number], BKN-4-[number], BKN-5-[number], BKN-6-[number], BKN-7-[number], or BKN-8-[number]. Survey began in 1938. "Date of completion Jan. 18, 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 1.2 pages61 × 51 cmislandora: api_1200https://digital.lib.uiowa.edu/node/23954engUnited States. Agricultural Adjustment AdministrationIowa Aerial SurveysUniversity of Iowa. Libraries. Map CollectionPublicPlymouth County, Iowa, 1938, aerial photomosaic indexImageryIowa--Plymouth CountyIowa1930-1940University of Iowa