The Middle Fork Kentucky River is a tributary of the North Fork Kentucky River, approximately long, in southeastern Kentucky. It rises in the Appalachian Mountains in southernmost Leslie County, approximately from the Virginia state line, and flows north through the Cumberland Plateau past Hyden. At Buckhorn, it is impounded to form the Buckhorn Lake reservoir. North of the reservoir it flows generally northwest and joins the North Fork in Lee County, approximately east of the confluence of the North and South forks at Beattyville. At Tallega, the river has a mean annual discharge of 792 cubic feet per second.