Some pedons have textures of sand to fine sandy loam below depths of 40 inches and some pedons contain up to 50 percent by volume of pebbles. Hoven soils are leached of salts to depths greater than 15 inches. Thunderegg soils have sand and gravel at depths of 25 to 50 inches. Durrstein soils are on level bottomlands along the larger drainageways and broad flats in glacial till plains. Slope gradients are less than 1 percent.
Surfaces are plane or concave.
These soils formed in clayey alluvium. Mean annual air temperature ranges from 45 to 52 degrees F, and the mean annual precipitation ranges from 17 to 26 inches. These are the competing Hoven soils and the Bon , Egas and Farmsworth . Hoven soils are in depressions. Bon soils do not have a natric horizon and are on higher positions in the landscape.