The Muskingum River, in northeastern Ohio, is about 180 km (112 mi) long. It is formed by the joining of the Walhonding and Tuscarawas rivers at Coshocton, then flows south and southeast past Dresden, Zanesville (where it receives the Licking River), and Stockport to empty into the Ohio River at Marietta. Locks and canals permit navigation in the lower part of the river.

The Ohio River is a 1,579-km-long (981-mi) tributary of the Mississippi that originates at the confluence of the Allegheny and Monongahela rivers in Pittsburgh, Pa. The Ohio flows through western Pennsylvania and along the West Virginia, Ohio, Kentucky, Indiana, and Illinois borders, discharging into the Mississippi at Cairo, Ill. The river's drainage basin of 528,000 sq./km. (204,000 sq./mi. ) supports a population of 25,000,000 and is one of the world's most productive industrial-agricultural areas. The Ohio flows past the major cities of Cincinnati, Ohio; Louisville, Ky.; and Evansville, Ind. The river valley's major industries are coal, oil, steel, chemicals, pottery, and tobacco. The Ohio's many tributaries include the Beaver, Kanawha, Scioto, Kentucky, Green, Wabash, and Tennessee rivers.

Rainfall along the river exceeds 1,016 mm (40 in) per year, and the mean annual temperature is 10-16 degrees C (50-60 degrees F). Even though it is prone to severe spring floods and summer droughts, the Ohio is navigable year-round because of flood-control systems and continual dredging. The 46 locks and dams that had been built along the river by 1929 began to be supplemented or replaced by 19 high-lift locks in 1955. The main traffic on the river consists of barges carrying bulk commodities. The Ohio River Valley Water Sanitation Commission was established in 1948 to control water pollution.

The Ohio River valley was occupied by Mound Builders as early as 500 BC. The area was inhabited by Shawnee Indians when Robert Cavelier, sieur de La Salle, explored it in 1669. The French built forts along the upper river valley, causing a conflict with the British that culminated in the French and Indian War (1754-63). The river was an important route for pioneers moving west.