Rock Bridge Memorial State Park  Rock Bridge Memorial State Park is a geological preserve and public recreation area encompassing , south of Columbia in Boone County, Missouri. The state park is noted for its excellent examples of karst landforms including the rock bridge, sinkholes, and an underground stream at the cave known as Devil's Icebox. The rock bridge was created by the collapse of a section of a cave which resulted in a small arch of rock being left to form a natural bridge over the creek. The boardwalk on the Devil's Icebox Trail gives access to the park's primary karst features and the opening at Connor's Cave. Park trails are available for hiking and cycling, and horseback riding is offered in the Gans Creek Wild Area.