Geological Survey (U.S.)1 map on 8 sheetsScale 1:250,000. Approximately 1 inch to 4 milesModified polyconic projectionW 96°37′ --W 90°07′ /N 43°30′ --N 40°22′JPEGui:sheetmaps_143engBureau of Public RoadsPublicIowa transportation map : railroads, highways, canals, air lanes, dredged channels, and pipe lines, 1934MapsIowa1930-1940University of Iowa