river, 259 mi (417 km) long, formed by the junction of the North Fork and the Middle Fork rivers, central Ky., and flowing NW to the Ohio River at Carrollton. Frankfort, Ky., is the river's largest city. The river is navigable for its entire length by means of locks. The Kentucky's upper course flows through a coal-mining district and the middle course through a deep gorge before entering the fertile bluegrass region.