The SMCS is saturated December through June and moist in at least some parts the remainder of the year. Neutral to moderately acid. At the soil surface to 2.5 feet. There are no other competing series in the same family. Crubas soils have more than 35 percent clay in the particle-size control section and less than 35 percent rock fragments.
Bywell soils are on stream terraces and have formed in alluvium derived from metamorphic rocks.
The seasonal water table is at the soil surface to 2.5 feet. Slopes range from 0 to 2 percent. These are the similar Crubas and the Croftshaw series. Croftshaw soils have less than 35 percent rock fragments in the particle-size control section. Bywell soils are used mainly for livestock grazing and wildlife habitat.