The Muskingum River is a tributary of the Ohio River, approximately long, in southeastern Ohio in the United States. An important commercial route in the 19th century, it flows generally southward through the eastern hill country of Ohio. Via the Ohio, it is part of the Mississippi River watershed. The river is navigable for much of its length through a series of locks and dams.
The name Muskingum derives from the Shawnee word mshkikwam 'swampy ground'. In LenapeMuskingum was taken to mean 'elk's eye' by folk etymology, as if < mus 'elk' + wəshkinkw 'its eye'. Moravian missionary David Zeisberger wrote that the Muskingum River was called Elk's Eye "because of the numbers of elk that formerly fed on its banks, these animals being found there even at the present time ..." Historically, it was also the name of a large Wyandot town along the river. As part of an expedition to assert French dominance throughout the entire Ohio valley, on August 15, 1749, a leaden plate claiming the region for France was buried at the confluence of the Muskingum and Ohio rivers by Pierre Joseph Céloron Noted frontier explorerChristopher Gist reached the Big Sandy Creek tributary of the river on December 4, 1751. Traveling downriver, he recorded arriving on December 14 at the western Wyandot town of Muskingum, at present-day Coshocton. There he remained for the following month. Marietta was founded in 1788 as the first permanent American settlement in the Northwest Territory, at the mouth of the Muskingum River on the Ohio River. The Big Bottom Massacre occurred along its banks in 1791. Zanesville was settled by European Americans in 1799 at the site where Zane's Trace crossed the Muskingum at the mouth of the Licking River. In the mid-19th century the Muskingum was an important commercial shipping route, with dams and locks controlling the water level to allow boats to travel up and down the river. With the decrease in use of water-based transportation in Ohio by the 1920s, the locks fell into disrepair. Since the 1960s, the locks have been repaired to enable pleasure craft to travel the entire navigable length of the river. The Muskingum waterway is one of the few remaining systems in the US to use hand-operated river locks. The navigation system has been designated a national Historic Civil Engineering Landmark. In 2006, it was designated "An Ohio Water Trail;" this designation provides for increased canoe access on the river. Located north of the Mason–Dixon line, from around 1812 to 1861 the Muskingum River was a major Underground Railroad route used by fugitive slaves escaping from the South on their journey north to Lake Erie and Canada.