Big River (Missouri)

River in the American state of Missouri
The river flows through or near the communities of Belgrade, Irondale, Park Hills, Bonne Terre, Morse Mill, Cedar Hill, and Byrnes Mill. Tributaries of the Big River include Flat River, Belews Creek, Turkey Creek, Mill Creek, Mineral Fork, Calico Creek, Heads Creek, Terre Bleue Creek, Ditch Creek, and Jones Creek.

Like many other Ozark streams, the Big River has entrenched meanders; its valley is typically about half a mile wide, sometimes much narrower, and the valley is usually from deep. This indicates that this river formed on a plain near sea level, which give the river its meandering nature, and then was subsequently uplifted, causing entrenchment. About 83 mile (134 km) are navigable; however, the remains of five small mill dams makes portage necessary, due to drops of several feet or high turbulence. Otherwise, the river is gentle for canoeing, with a Class I difficulty rating. Public parks are adjacent to most of these dams, and are popular fishing spots. Due to steady infeed of springwater, this river is navigable in all seasons. Major pollution sources near Park Hills are due to historic mining activities, which including erosion from mine tailings piles and leaking mine dams. Major gamefish commonly found in the river include largemouth bass, smallmouth bass, spotted bass, rock bass, longear sunfish, bluegill, channel catfish, flathead catfish, and redhorse suckers.

The name "Big River" is a translation of the French Grande Rivière. According to the National Weather Service, the maximum flood stage of the Big River at Byrnes Mill occurred on August 21, 1915, and was 30.20 feet (9 m), with a flow of roughly per second. Flood stage at Byrnes Mill is 16 feet (5 m). The lowest flow measured, per second, was recorded on August 30, 1936. The average annual discharge here is per second. August is the month with the lowest average flow, while April has the highest average flow.