Johnson's Shut-Ins State Park
Johnson's Shut-Ins State Park is a public recreation area covering on the East Fork Black River in Reynolds County, Missouri. The state park is jointly administered with adjoining Taum Sauk Mountain State Park, and together the two parks cover more than sixteen thousand acres in the St. Francois Mountains region of the Missouri Ozarks. The term "shut-in" refers to a place where the river's breadth is limited by hard rock that is resistant to erosion. In these shut-ins, the river cascades over and around smooth-worn igneous rock, creating a natural water park that is used by park visitors when water levels are not dangerously high. Geology The bedrock of the area is an erosion resistant rhyolite porphyry and dark colored diabase dikes of Proterozoic age. Waters of the East Fork Black River became confined, or "shut-in", to a narrow channel following fractures and joints within the hard igneous rock. Water-borne sand and gravel cut deeply even into this erosion-resistant rock, carving potholes, chutes and canyon-like gorges. History Precolonial history The Osage Nation hunted in this area. After colonization The park was the mid-19th century homestead of the Johnston family, Scotch-Irish immigrants who had moved west from the Appalachian region. When