The Roic series consists of very shallow and shallow, well drained soils that formed in residuum and colluvium derived from tuffaceous sedimentary rocks.
Roic soils are on pediments and hills.
Slopes are 2 to 50 percent. Reaction - Moderately alkaline or strongly alkaline. Effervescence - Noneffervescent to strongly effervescent. Calcium carbonate equivalent - 0 to 10 percent. Fine sandy loam, very fine sandy loam, sandy loam, or loam.