Big River (Missouri)

The Big River is a tributary of the Meramec River in east-central Missouri. The river rises in western Iron County  near the summit of Johnson Mountain and the locale of Enough; it flows through Washington County, Saint Francois County, and Jefferson County. It forms part of the boundary between Jefferson County and Saint Francois County and also part of the boundary between Jefferson County and Washington County. It empties into the Meramec River opposite Eureka  where the Meramec forms the border between Jefferson County and Saint Louis County. The river flows through Washington State Park, St. Francois State Park, and the Lead Belt mining district. The elevation of the river at its source is approximately above sea level and at its mouth about . The length of the river is approximately , while the airline distance between source and mouth is about . Its watershed area is .