Oklahoma Level 4 Ecoregions Map
| er25b - Rolling Sand Plains |
| er25c - Moderate Relief Plains |
| er25e - Rolling Cropland and Range |
| er26a - Cimarron Breaks |
| er26b - Flat Tablelands and Valleys |
| er26c - Caprock Canyons, Badlands, and Breaks |
| er26f - Mesa de Maya/Black Mesa |
| er27d - Wellington-McPherson Lowland |
| er27h - Red Prairie |
| er27i - Broken Red Plains |
| er27k - Wichita Mountains |
| er27l - Pleistocene Sand Dunes and Sandsage Grassland |
| er27m - Red River Tablelands |
| er27n - Gypsum Hills |
| er27o - Cross Timbers Transition |
| er27p - Salt Plains |
| er27q - Rolling Red Hills |
| er27r - Limestone Hills |
| er28a - Flint Hills |
| er29a - Cross Timbers | er29a - Eastern Cross Timbers |
| er29c - Western Cross Timbers | er29c - Grand Prairie |
| er29g - Arbuckle Uplift | er29g - Northwestern Cross Timbers |
| er29i - Arbuckle Mountains | er29i - Northern Post Oak Savanna |
| er35b - Floodplains and Low Terraces | er35b - Pleistocene Fluvial Terraces |
| er35d - Cretaceous Dissected Uplands | er35d - Red River Bottomlands |
| er35h - Blackland Prairie | er35h - Athens Plateau |
| er36b - Central Mountain Ranges | er36b - Fourche Mountains |
| er36e - Western Ouachitas | er36e - Western Ouachita Valleys |
| er37a - Scattered High Ridges and Mountains | er37a - Arkansas River Floodplain |
| er37d - Arkansas Valley Plains | er37d - Lower Canadian Hills |
| er38b - Lower Boston Mountains | er38b - Springfield Plateau |
| er39b - Dissected Springfield Plateau-Elk River Hills | er39b - Osage Cuestas |
| er40d - Cherokee Plains |
Based on Ecoregions developed by the EPA this map describe areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources, as well as similarity of climate that can assist Oklahoma gardenders.
