Griswold and Ringwood soils occupy slightly higher positions on the landscape and formed in glacial till with a thin surface layer of loess. Grellton and Plano soils occupy similar positions on the landscape. Grellton soils do not have mollic epipedons. Plano soils formed in 40 to 60 inches of loess or other silty deposits and in underlying loamy stratified outwash or sandy loam till. Most areas are cropped.
Principal crops are corn, small grain, and hay.
Native vegetation was mixed grasses. The series is of moderate extent.