It has been estimated that of the original tallgrass prairie that once covered millions of acres across the midwest, as little as 1% remains. Tallgrass prairie is much more than just grasses and includes hundreds of species of shrubs, forbs, and wildflowers and a host of birds, mammals, reptiles, amphibians and insects that depend upon the vegetation composition and structure, either directly or indirectly. The refuge is between bottomland forest and prairie and it is likely that both existed here in pre-settlement times.
At least 14 species of native grasses can be found in refuge grasslands with the dominant species being big bluestem, little bluestem, switchgrass, indian grass, and Canada wild rye. There are at least 160 species of native forbs and wildflowers found in refuge grasslands.