tributary of the Ohio River in north-central Kentucky, U.S., and navigable along its 259-mile (417-km) course by means of locks. It is formed by the confluence of North, Middle, and South forks near Beattyville in Lee county and empties into the Ohio at Carrollton. The North Fork rises in the Cumberland Mountains in Letcher county, near the Virginia line, and flows 168 miles (270 km) southwest, then northwest. The Middle and South forks originate in Leslie and Bell counties in the Cumberlands, and both flow generally north for 97 miles and 75 miles (156 km and 120 km), respectively, before joining the main stream.