Tester, Allen C. (Allen Crawford), 1897-1 color mapJPEG20004369680990071386540202771file name: 31858060777061.jp2barcode: 31858060777061islandora: sheetmaps_99(OCoLC)07638459812847694https://digital.lib.uiowa.edu/node/575823engIowa Geological SurveyPublicGeologic map of Iowa, 1937MapsIowa1930-1940University of Iowa