A geologic map of the park: NPS Wind Cave National Park Geologic Map, where Mp is the Mississippian Pahasapa (Madison) Limestone, Phm is the Pennsylvanian Minnelusa Formation, Po is the Permian Opeche Shale, Pm is the Minnekahta Limestone, TRPs is the Triassic Spearfish Formation, Tw is the Tertiary White River Group, while Qal and Qt are Quaternary alluvial deposits (Source)