The Texas savanna originally may have been largely mixed prairie grassland, but currently is a high-shrub savanna. It occupies the western end of Gulf Coastal Plain and the southern end of the Great Plains. Elevation ranges from 200 meters near the Gulf of Mexico to over 1000 meters at the western edge of the Edwards Plateau. The area is relatively flat but is cut through by ravines and arroyos. Precipitation comes mostly in summer and ranges from 50 to 75 centimeters.
Potential evaporation is roughly twice that of precipitation.
The soils of the region include mollisols, alfisols, vertisols, and entisols. The entisols are covered by the mesquite-liveoak savanna type. Alfisols support the mesquite oak savanna. The entire area could be classed a mesquite shrubland. Mesquite-liveoak savanna occurs in the West Gulf Coast Plain and has live oaks and mesquites as dominants of the overstory.