Stone Mill Spring Branch is owned by the USDA Forest Service (USFS) and cooperatively managed by the USFS, Missouri Department of Conservation, and the Fort Leonard Wood Natural Resources Branch. Park and walk down a trail that is approximately .25 mile to the beautiful Stone Mill Spring. This is a day use recreation area along the Big Piney River, managed as a trout fishery. Picnic tables, benches and grills are available, as well as a 1-mile hiking trail that provides views of the Big Piney River. Stone Mill Spring is a very narrow spring that flows 18 million gallons a day, before it runs down and empties into the Big Piney River. That is enough water to fill 27 Olympic swimming pools each day. It is named after a historical mill that operated in the 1880’s. This site is only accessible and mostly used by those on the Fort Leonard Wood Base.