The slopes are concave and mostly of less than 1 percent, ranging up to 3 percent. The soils formed in medium to moderately fine textured silty alluvial materials low in carbonates, with small amounts of eolian material. The climate is arid to semiarid with mean annual precipitation of 10 to 14 inches. Holloman and Reeves soils are on the uplands and have gypsic horizons. Reakor soils are on the uplands, knolls of the uplands and have petrocalcic horizons.
Permeability is moderately slow.
Runoff is slow to medium. The soil is subject to occasional, very brief overflow. Crops are mainly alfalfa, cotton and sorghum. Native vegetation is mainly giant sacaton, alkali sacaton, vine-mesquite, tobosa, blue grama, buffalograss, burrograss and widely spaced mesquite and cholla cactus. The southern Pecos and Rio Grande Valleys of Texas and New Mexico.