Beginning in western Pennsylvania at the confluence of the Allegheny River and Monongahela River in Pittsburgh, the Ohio River helps form parts of the borders of Ohio, Kentucky, Indiana and Illinois, although no part of the river actually belongs to Illinois. Its northern banks are actually a part of Kentucky's northern state line. It flows by several major cities including Wheeling, Cincinnati, Louisville, Paducah, and Evansville.
The river passes by the Illinois cities of Old Shawneetown, Cave-in-Rock, Golconda, Metropolis and Mound City before ending south of Cairo and the Fort Defiance State Historical Site where it empties into the Mississippi River.
Recreational areas gracing the shores of the river include Cave-in-Rock State Park, Shawnee National Forest and Fort Massac State Park.