Ecoregions of Oklahoma
| ECOREGION NAME | DESCRIPTION OF ECOREGION |
| Black Mesa | Rocky Mountain foothills |
| Western High Plains | Shortgrass prairie |
| Southwestern Tablelands | Shinnery oak scrub |
| Central Great Plains | Mixed grass prairie |
| Flint Hills | Tallgrass prairie |
| Central Oklahoma/Texas Plains | Crosstimbers |
| Central Irregular Plains | Tallgrass prairie; caves |
| Ozark Highlands | Oak hickory forests |
| Arkansas Valley | Prairie; bottomland hardwood forest |
| Ouachita Mountains | Prairie savanna; moist hardwood forest |
| South Central Plains | Moist forest; cypress swamps |
| Big River | Large, wide sandy river |