Shale Hollow Park is characterized by 30- to 4-foot shale cliffs that line Big Run, a tributary to the Olentangy River. Mature red and white oaks grow on the cliff; other trees include American hazelnut, American beech, sassafras, serviceberry, and spicebush in the understory. Cottonwoods, sycamore and Ohio buckeyes are present in the Big Run floodplain. Round rock formations, called concretions – embedded in the shale – have been exposed after centuries of erosion. The park includes an off-trail exploration area, where visitors can wade in the stream, and see the shale cliffs and concretions up close. The park also includes reservable business meeting space in the McKay Lodge.