where does the merrimack river start in missouri
Meramec River The Meramec River (/ˈmɛrɪmæk/) is one of the longest free-flowing waterways in Missouri, draining 3,980 square miles (10,300 km2)[1] while wandering 218 miles (351 km)[2] 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, just south of St. James. The Meramec's size increases at the confluence of the Dry Fork, and its navigability continues until the river enters the Mississippi at Arnold, Missouri.
Shenandoah River The Shenandoah River is formed northeast of Front Royal near Riverton, by the confluence of the South Fork and the North Fork. It flows northeast across Warren County, passing underneath Interstate 66 1 mile (1.6 km) from its formation. Beyond the I-66 bridge the river flows through a set of bends before turning to the northeast again, crossing into Clarke County 11 miles (18 km) below I-66. Five miles (8 km) downriver from the Clarke County border, the Shenandoah passes under U.S. Route 50 and then passes through a triple bend. 14.5 miles (23.3 km) below the Route 50 bridge, the river passes underneath State Route 7 and then continues northeast another 8 miles (13 km) where it crosses into Jefferson County in West Virginia, in the extreme eastern tip of the state. Once in West Virginia the river completes six large bends before joining with the Potomac from the southwest near Harpers Ferry. The confluence is on the West Virginia-Maryland border and 0.4 miles (0.64 km) from the Virginia-West Virginia border.[4]