The elevation of this region is approximately 1,500 feet above mean sea level. Soils in this region consist of calcareous clay, clay loams, sandy loams, sands, and caliche. Below the Caprock, the Double Mountain Fork of the Brazos River and the Salt Fork of the Brazos River flow through the Rolling Plains. The two forks join at the eastern boundary of the Rolling Plains forming the Brazos River. The Rolling Plains range from nearly level to rolling and possess moderate surface drainage.
Saline soils are common, as are pockets of sand and clay loams.
The Brazos enters the Cross Timbers and Prairies region of the state shortly after the confluence of the Double Mountain Fork and the Salt Fork. This area is characterized by a rugged topography and wide variances in geologic formations and soils. Soils range from sands and sandy loams, to clay and alluvial loams. Upon leaving the Cross Timbers and Prairies region, the Brazos River flows through the intermingled regions of the Blackland Prairie and the Post Oak Savannah. Here the topography changes from the ruggedness of the Cross Timbers and Prairies to gently rolling hills.