Ohio River course forms the northern borders of West Virginia and Kentucky; and the southern borders of Ohio, Indiana and Illinois, until it joins the Mississippi River at the city of Cairo, Illinois. Where the Ohio joins the Mississippi is the lowest elevation in the state of Illinois, at . The Ohio River, which flows westward from Pittsburgh, Pennsylvania, to Cairo, Illinois, is the largest tributary, by volume, of the Mississippi River in the United States. At the confluence, the Ohio is considerably bigger than the Mississippi. Measured by long-term mean discharge in cubic feet per second and cubic meters per second,
Big Sandy River (Ohio River tributary) It joins the Ohio between Catlettsburg, Kentucky and Kenova, West Virginia, west of Huntington, West Virginia, at the common boundary between West Virginia, Kentucky, and Ohio. The river is navigable and carries commercial shipping, primarily coal mined in the immediate region. The name of the river comes from the presence of extensive sand bars. The Native American names for the river included "Tatteroa", "Chatteroi", and "Chatterwha" which had similar meaning to the English name. It was known to the Lenape as "Sikeacepe", meaning "Salt River", from the presence of salt licks on the river ("see": Licking River). The name "Big