| 25b Rolling Sand Plains |
| 25c Moderate Relief Plains |
| 25e Canadian/Cimarron High Plains |
| 26a Canadian/Cimarron Breaks |
| 26b Flat Tablelands and Valleys |
| 26c Caprock Canyons, Badlands, and Breaks |
| 26f Mesa de Maya/Black Mesa |
| 27d Prairie Tableland |
| 27h Red Prairie |
| 27i Broken Red Plains |
| 27k Wichita Mountains |
| 27l Pleistocene Sand Dunes |
| 27m Red River Tablelands |
| 27n Gypsum Hills |
| 27o Cross Timbers Transition |
| 27p Salt Plains |
| 27q Rolling Red Hills |
| 27r Limestone Hills |
| 28a Flint Hills |
| 29a Northern Cross Timbers |
| 29b Eastern Cross Timbers |
| 29c Western Cross Timbers |
| 29d Grand Prairie |
| 29g Arbuckle Uplift |
| 29h Northwestern Cross Timbers |
| 29i Arbuckle Mountains |
| 33a Northern Post Oak Savanna |
| 35b Floodplains and Low Terraces |
| 35c Pleistocene Fluvial Terraces |
| 35d Cretaceous Dissected Uplands |
| 35g Red River Bottomlands |
| 35h Blackland Prairie |
| 36a Athens Plateau |
| 36b Central Mountain Ranges |
| 36d Fourche Mountains |
| 36e Western Ouachitas |
| 36f Western Ouachita Valleys |
| 37a Scattered High Ridges and Mountains |
| 37b Arkansas River Floodplain |
| 37d Arkansas Valley Plains |
| 37e Lower Canadian Hills |
| 38b Lower Boston Mountains |
| 39a Springfield Plateau |
| 39b Dissected Springfield Plateau-Elk River Hills |
| 40b Osage Cuestas |
| 40d Cherokee Plains |