They formed in pediments veneered with volcanic alluvium. Slope ranges from 0 to 60 percent. The average annual precipitation is 22 inches. The mollic epipedon is 8 to 15 inches thick.
Reaction is slightly acid.
It ranges from gravelly and cobbly sandy clay loam to very gravelly and very cobbly sandy loam and clay loam and averages 35 to 60 percent rock fragments. It ranges from very gravelly and very or extremely cobbly sandy loam to very cobbly and very gravelly loam. Blaine, Bowen, Buena Vista, Elwood, Nathale, Nathrop, Parkview, Winada and Woodhall soils have bedrock at depths of 20 to 40 inches. Chamberlain soils have silica coating on the rock fragments. Ess, Ezbin, Fornor, Forsey, Fourme, Fourmile, Geertsen, Libeg, Norriston, Packer, Quander, Sedgway, Tahquats, and Zeebar soils do not have a calcic horizon.