Chihuahuan Deserts, Edwards Plateau, High Plains, Southwestern Tablelands
Chihuahuan Basins and Playas, Chihuahuan Desert Grasslands, Chihuahuan Montane Woodlands, Low Mountains and Bajadas, Stockton Plateau
Balcones Canyonlands, Semiarid Edwards Plateau
Canadian/Cimarron High Plains, Llano Estacado
Canadian/Cimarron Breaks, Caprock Canyons Badlands Breaks, Flat Tablelands and Valleys