Alama soils have less than 15 percent calcium carbonate in the control section. Riveroad soils do not have Bk horizons. Copita soils have fine-loamy control sections and have mean annual soil temperature of more than 72 degrees F. Hoban, Midessa, and Reagan soils have calcic horizons within 40 inches of the surface. Slopes are plane and gradients are generally less than 1 percent, but range up to 3 percent. The parent material is of moderately fine and fine textured, calcareous sediments from limestone or from a variety of sedimentary and igneous rocks.
Climate is semiarid to arid.
Mean annual precipitation ranges from 10 to 18 inches and mean annual temperatures range from 60 degrees to 68 degrees F. Frost-free days range from 210 to 240 and elevation ranges from 1,500 to 4,000 feet. Thornthwaite P-E indices range from 14 to 25. These are the Hoban and Reagan series and the Conger , Dalby , Monahans , Sanderson , Upton , and Verhalen series. Conger and Upton soils are shallow to indurated caliche. Dalby and Verhalen soils have intersecting slickensides and gilgai microrelief.