Harrison County is located in southwestern Iowa, being separated by the Missouri River from Nebraska, on the west and in the fourth tier of counties It lies entirely in the Missouri loess soil area and the soils of the county are, therefore, mainly of loessial origin.
Stevenson, W. H. and Brown, P. E., "Soil Survey of Iowa, Report No. 55—Harrison County Soils" (1929). Soil Survey Reports. 65.