These soils formed in brownish calcareous clay that is apparently ancient alluvium several feet thick. The climate is dry subhumid. Average annual precipitation ranges from 20 to 28 inches, and the mean annual air temperature ranges from 65 degrees to 68 degrees F. Thornthwaite annual P-E index ranges from 32 to 44. These are the competing Randall , Roscoe , and Tobosa series and the Nuvalde and Rowena series. Nuvalde and Rowena soils lack intersecting slickensides and have a mollic epipedon.
Water enters the soil rapidly when the soil is dry and cracked.
Used for growing cotton, grain sorghums, and small grains. The native vegetation is mostly buffalograss, curlymesquite grass, threeawns, Texas wintergrass, and a sparse growth of mesquite trees, tasajillo, and cacti. Mainly in west-central Texas near the contact of the Edwards Plateau and Rolling Plains. The series is of moderate extent with about 10,000 acres. This soil would have been classified in the Grumusol great soil group.