The Osobb series consists of very shallow and shallow to a duripan, well drained soils that formed in residuum and colluvium derived from volcanic rocks.
Osobb soils are on hills and plateaus.
Slopes are 4 to 50 percent. The mean annual precipitation is about 5 inches and the mean annual temperature is about 50 degrees. Depth to bedrock - 9 to 20 inches to a lithic contact. Lithology of fragments are volcanic rocks such as tuff and rhyolite. Slightly alkaline to strongly alkaline.