State Line Serpentine Barrens is a 60-square-mile (160 km2) tract of serpentine barrens in Pennsylvania and Maryland in the eastern United States. The protected area is actually an assemblage of six tracts owned by a combination of the Nature Conservancy, the State of Pennsylvania, two counties, a township, and private owners. The largest tract is Nottingham County Park in Chester County, which has also been deemed a National Natural Landmark. The second-largest is Goat Hill Serpentine Barrens, jointly owned by the Nature Conservancy and the Pennsylvania Forestry Department, and the third-largest, Chrome Serpentine Barrens, is jointly owned by Elk Township and the Nature Conservancy. Rock Springs Preserve in Lancaster County is managed by the Lancaster Conservancy.