The Riverdale series consists of somewhat poorly drained soils formed in sandy glacial drift.
Permeability is moderately rapid in the solum and very rapid in the underlying gravelly sand.
Slope gradients range from 0 to 6 percent. Solum thickness ranges from 24 to 40 inches and corresponds to depth of free carbonates. Gravel content ranges from 2 to 25 percent in the solum and from 20 to 50 percent in the 2C horizon. The solum ranges from slightly acid to mildly alkaline. The Ap horizon has hue of 10YR, value of 2 to 4, and chroma of 1 to 3.