Decatur County lies in the south-central part of Iowa, immediately bordering the state of Missouri. Leon, the centrally located county seat, is situated 60 miles south of Des Moines, the state capital, and 115 miles east and a little south of Council Bluffs.
Simsonson, Roy W., "Soil Survey of Iowa, Report No. 80—Decatur County Soils" (1941). Soil Survey Reports. 72.