Gypsiorthids are in closed basins. Natragids and Torrerts are on basin floors. Torrifluvents are on flood plains and Torripsamments are on sandy uplands. These soils have a thermic temperature regime, aridic moisture regime, and mixed or carbonatic mineralogy. Soils are well drained, shallow to deep, and medium textured.
Soil moisture is limited for use by vegetation during most of the growing season.
Potential Natural Vegetation. Species include desert shrubs in association with short to mid height grasses and oak savannas. Typical large to medium size herbivores and carnivores include pronghorn, coyote, swift fox, ringtail, hooded skunk, ocelot, and collared peccary. Smaller herbivores include desert shrew, desert cottontail, Mexican ground squirrel, yellow-faced pocket gopher, Nelson's pocket mouse, and Merriam's kangaroo rat. Several bats, western mastiff and yuma myotis, are present here.