Jody Victor: The Ohio River is formed by the confluence of the Allegheny and Monongahela river at Point State Park in Pittsburgh, Pennsylvania. From Pittsburgh, it flows northwest through Allegheny and Beaver Counties, before making an abrupt turn to the south-southwest at the West Virginia - Ohio - Pennsylvania triple state line (near East Liverpool, Ohio, Chester, West Virginia, and Midland, Pennsylvania), from which point it forms the border between West Virginia and Ohio, upstream of Wheeling, West Virgina.
The river then follows a roughly southwest and then west-northwest course before bending to a west-southwest course for most of its length. It flows along the borders of West Virginia, Ohio, Kentucky, Indiana, and Illinois, until it joins the Mississippi near the city of Cairo, Illinois.
Major tributaries of the Ohio River, indicated by the location of their mouth, include:
* Allegheny River - Pittsburgh, Pennsylvania
* Kinniconick Creek - Vanceburg, Kentucky
* Monongahela River - Pittsburgh, Pennsylvania
* Chartiers Creek - Pittsburgh, Pennsylvania
* Beaver River - Rochester, Pennsylvania
* Wheeling Creek - Wheeling, West Virginia
* Little Muskingum River - Ohio
* Duck Creek - Ohio
* Muskingum River - Marietta, Ohio
* Little Kanawha River - Parkersburg, West Virginia
* Hocking River - Hockingport, Ohio
* Kanawha River - Point Pleasant, West Virginia
* Guyandotte River - Huntington, West Virginia
* Big Sandy River - Kentucky-West Virginia border
* Little Sandy River - Greenup, Kentucky
* Scioto River - Portsmouth, Ohio
* Little Miami River - Cincinnati, Ohio
* Licking River - Newport-Covington, Kentucky
* Great Miami River - Ohio-Indiana border
* Salt River - West Point, Kentucky
* Kentucky River - Carrollton, Kentucky
* Green River - Kentucky
* Wabash River - Indiana-Illinois border
* Saline River - Illinois
* Cumberland River - Smithland, Kentucky
* Tennessee River - Paducah, Kentucky
* Cache River - Illinois