Dewey Heights Prairie rests atop a southwest-facing bluff between 800-870 feet high overlooking the Mississippi River. The cap rock is Ordovician-age dolomite covered only partially by thin soil with exposed cap rocks, ledges, and cliffs. A dry, limey prairie dominated by big and little blue-stem, side-oats grama, hairy grama, June grass, Indian grass, and needle grass occupies the steep slopes. There is also a diversity of native prairie forbs from spring blooming pasque flower, wood betony, and shooting star to summer blooming butterfly weed and compass plant and asters and goldenrods in the fall. Other species include marble-seed, golden alexanders, false toadflax, smooth cliff brake, germander, and false boneset. Two rare plants grow here the state-threatened prairie Indian plantain (Arnoglossum plantagineum) and cliff goldenrod (Solidago sciaphila). The site is also home to numerous rare animals including lark sparrow (Chondestes grammacus), field sparrow (Spizella pusilla), and grasshopper sparrow (Ammodramus savannarum), numerous reptiles including the prairie ring-necked snake (Diadophis punctatus), and seven Lepidopterans including the Ottoe skipper (Hesperia ottoe) and columbine dusky-wing (Erynnis lucilius). Dewey Heights Prairie is owned by the DNR and was designated a State Natural Area in 1952.