Sand Bridge State Park is a Pennsylvania state park on 3 acres (0.01 km2) in Lewis Township, Union County, Pennsylvania in the United States. The park is the smallest state park in Pennsylvania and consists of a picnic area just off Pennsylvania Route 192. It has three picnic pavilions that were built by the Civilian Conservation Corps during the Great Depression. Rapid Run, a trout stream that is stocked by the Pennsylvania Fish and Boat Commission, flows through Sand Bridge State Park. The park attracted 17,000 visitors in 2008. The name Sand Bridge remains a mystery. No one, according to the parks official website knows why the area is known as Sand Bridge. The park is surrounded by Bald Eagle State Forest and became a Pennsylvania State park in 1978.