Loam, fine sandy loam or very fine sandy loam. Moderately alkaline to very strongly alkaline. These are the Osoll , Otomo , and Pahroc series. Osoll soils have hard bedrock between 20 and 40 inches. Otomo and Pahroc soils do not have bedrock within 60 inches and occur on fan remnants.
Osobb soils are on hills and plateaus.
They formed in residuum and colluvium derived from volcanic rocks. Slopes are 4 to 50 percent. Elevations range from 4,400 to 7,000 feet. The climate is cool-arid with cool, moist winters and hot, dry summers. These are the Celeton , Gabbs and Pirouette soils.