Volume of rock fragments range from 10 to 40 percent. Reaction is neutral to slightly alkaline. The C horizon has hue of 10YR, value of 3 to 6, and chroma of 1 to 4. It is very gravelly or extremely gravelly analogs of loamy coarse sand or sand. Volume of rock fragments range from 35 to 78 percent.
Reaction is slightly alkaline or moderately alkaline and carbonates are present.
Rodman series is the only one in the family. Closely related soils are the Alpena , Casco , Kars , Kiva , and Lorenzo series. Alpena and Kiva soils have a frigid soil temperature regime. Casco soils do not have a mollic epipedon and have an argillic horizon. Kars and Lorenzo soils have an argillic horizon.