The hills are moderately sloping to steep, and the plateaus are broad and gently sloping to undulating. Average annual precipitation -625 to 750 mm. About three-fourths of the precipitation falls during the growing season. The rainfall is adequate for range grasses but is marginal for crops because of extended high temperatures and high evaporation and transpiration rates during the summer. Only a few rivers and large streams flow throughout the year, and irrigation from these sources is limited.
Deep wells provide water for some irrigation.
Shallow and deep wells and ponds provide water for livestock and for domestic needs. Most of the soils are Ustalfs. They are somewhat gravelly and moderately coarse textured and have a thermic temperature regime, an ustic moisture regime, and mixed mineralogy. Such forbs as orange zexmania, bushsunflower, Engelmann-daisy, and trailing ratany grow throughout the area. A mid grass community with scattered individual or groves of live oak and post oak grows on the shallow and more droughty soils.