Buchanan County is located in eastern central Iowa in the third tier of counties west of the Mississippi River. It is chiefly in the Iowan drift soil area and hence most of the soils of the county are of drift origin. There is a small area of loess soils, probably derived from the Mississippi loess deposit.
Brown, P. E.; Benton, T. H.; Meldrum, H. R.; and Bennett, R. E., "Soil Survey of Iowa, Report No. 67—Buchanan County Soils" (1932). Soil Survey Reports. 53.