Fayette county is located in northeastern Iowa in the second tier of counties west of the Mississippi river and in the second tier south of the Minnesota state line. The location is shown in the accompanying sketch map. It lies partly in the Iowan drift soil area and partly in the Mississippi loess, and hence the soils of the county are of loessial and glacial origin. The larger part of the county, however, slightly less than two-thirds of the total area is covered by drift soils.
Stevenson, W. H. and Brown, P. E., "Soil Survey of Iowa, Report No. 30—Fayette County Soils" (1923). Soil Survey Reports. 22.