The Ohio River

Ohio river watershed

Illustration: The Ohio River Foundation,

With the 1,200-mile extension of the Lewis and Clark National Historic Trail in May 2019, a fourth major North American river became an official part of the Trail – the Ohio River, joining the Mississippi, Missouri, and Columbia Rivers.

Beginning at Pittsburgh, Pennsylvania, the Ohio is formed by the confluence of the Allegheny and Monongahela Rivers. It ends 981 miles later at Cairo, Illinois when it empties into the Mississippi. The average depth is 24 feet, with the deepest section of 130 feet near Louisville, Kentucky.

The Ohio receives its name from the Iroquois word, “O-Y-O,” meaning “the great river.” France first claimed the watershed of “La Belle Viviere” (the beautiful river). England later controlled the same land based on a purchase from the Native tribes in 1744, which ultimately led to the French and Indian War from 1756 to 1763. During the late 18th century, the Ohio River served as the southern border of what would later be known as the Northwest Territory. It also was generally the dividing line between British settlements in Kentucky and Native communities in the Ohio Country.

As early settlers pushed into the Northwest Territory, most used the river as a way to transport their families and possessions, forming many new settlements along the banks, including Marietta, Steubenville, and Cincinnati. During the 19th century, the Ohio became an important commercial route for residents in Ohio, Kentucky, Indiana, and Illinois. Farmers and manufacturers shipped their crops and goods on flatboats or barges downstream to the Mississippi River, eventually stopping in New Orleans where freight was loaded onto ocean-going vessels departing to eastern seaboard ports or international destinations.

The first dam was completed on the river in 1885. Today there are 20 dams along the entire river. Commercial traffic on the Ohio has increased from about 5 million tons of cargo in 1917 (the first year records were kept) to over 230 million tons per year today.

Lewis & Clark National Historic Trail

Last updated: December 30, 2019