Rocky Run Oak Savanna

State Natural Area (No. 220)

Location: Within Rocky Run Fishery Area, Columbia County. T11N-R9E, Section 1. T11N-R10E, Sections 5, 6. T12N-R10E, Sections 31, 32. 441 acres.

Access: From the intersection of State Highways 16 and 22 south of Wyocena, go south on 22 1.9 miles to the Rocky Run Fishery Area parking area west of the road. Walk west and south on an access lane 0.7-mile into the area. Or continue south on 22 another 1.3 miles, then west on County B 1.5 mile, then north on Dunning Road 0.5 mile to a Rocky Run Fishery Area parking area east of the road. Walk east along the access lane, then north across Rocky Run Creek into the natural area.

Description: Rocky Run Savanna occupies widely differing topography on a south-facing slope above Rocky Run Creek. The eastern portion is gently rolling, while the west is very steep and dissected containing two sheer-walled box canyons cut through the Cambrian sandstone. As the topography varies so does the bur, white, and black oak savanna canopy structure. The canopy is open on the upper slopes and nearly closed on the relatively flat lower slope with open grown oaks and scattered groves of oak, hickory, black cherry, and red cedar interspersed with prairie. Dominant grasses are little blue-stem, Indian grass, and side-oats grama. The variation in topography, shading, and soils provides for a mosaic of groundlayer species. More than 100 species with prairie affinities have been recorded including many rare plants such as woolly milkweed (Asclepias lanuginosa), Hill's thistle (Cisium hillii), prairie false dandelion (Agoseris cuspidata), and Flodman’s thistle (Cirsium flodmanii). The dry, sandy conditions also support a notable concentration of rare animals including slender glass lizard (Ophisaurus attenuatus), Blanding’s turtle (Emydoidea blandingii), field sparrow (Spizella pusilla), vesper sparrow (Pooecetes gramineus), dog-face butterfly (Colias cesonia), coral hairstreak (Harkenclenus titus), and Reakert’s blue (Hemiargus isola). Management activities of brushing and prescribed burns are needed to help maintain and restore the oak opening. Rocky Run Savanna is owned by the DNR and was designated a State Natural Area in 1988.