The Meramec River (), sometimes spelled Maramec River is one of the longest free-flowing waterways in the U.S. state of Missouri, draining 3,980 square miles (10,300 km2) while wandering 218 miles (351 km) from headwaters near Salem to where it empties into the Mississippi River near St. Louis at Arnold and Oakville. The Meramec watershed covers six Missouri Ozark Highland counties—Dent, Phelps, Crawford, Franklin, Jefferson, and St. Louis—and portions of eight others—Maries, Gasconade, Iron, Washington, Reynolds, St. Francois, Ste. Genevieve, and Texas. Between its source and its mouth, it falls 1,025 feet (312 m). Year-round navigability begins above Maramec Spring, ... Source: Wikipedia