The Theriot series consists of very shallow and shallow, well drained soils that formed in residuum and colluvium derived from limestone and dolomite.
Theriot soils are on mountains, hills, ridges, and pediments.
Slopes are 8 to 75 percent. Reaction - Moderately alkaline to very strongly alkaline. Loam, fine sandy loam, or sandy loam. Koynik soils have mean annual soil temperature of 47 to 52 degrees F. and are not moist for 10 days in the summer. Potosi soils have 50 to 70 percent pebbles and average 0 to 10 percent cobbles and stones in the particle-size control section.