1900. Iowa. Board of Railroad Commissioners. 1 map Scale [ca. 1:506,880]. 8 miles to 1 inch W 96°37′--W 90°07′/N 43°30′--N 40°22′. Kenyon Print. & Mfg.
1915. Iowa. Board of Railroad Commissioners. 8 miles = 1 inch; 1 map Material in the public domain. No restrictions on use. University of Iowa. Libraries. Map Collection. Rand McNally and Company.