The Williamson series consists of deep, moderately well drained soils on lake plains and uplands. They are nearly level to sloping soils formed in silty or very fine sandy lacustrine or eolian deposits.
Permeability is moderate above the fragipan and slow or very slow in the fragipan.
Slope ranges from 0 to 15 percent. The thickness of solum ranges from 35 to 60 inches. Depth to the top of the fragipan ranges from 15 to 24 inches. Depth to bedrock is greater than 60 inches. Rock fragments range from 0 to 5 percent throughout the soil.