<Tr> <Td_colspan="2"> Map of the Cumberland River Watershed </Td> </Tr> <P> The Cumberland River is a major waterway of the Southern United States . The 688 - mile - long (1,107 km) river drains almost 18,000 square miles (47,000 km) of southern Kentucky and north - central Tennessee . The river flows generally west from a source in the Appalachian Mountains to its confluence with the Ohio River near Paducah, Kentucky, and the mouth of the Tennessee River . Major tributaries include the Obey, Caney Fork, Stones, and Red rivers . </P> <P> Although the Cumberland River basin is predominantly rural, there are also some large cities on the river, including Nashville and Clarksville, both in Tennessee . In addition, the river system has been extensively developed for flood control, with major dams impounding both the main stem and many of its important tributaries . </P> <P> Its headwaters are three separate forks that begin in Kentucky and converge in Baxter, KY, located in Harlan County . Martin's Fork starts near Hensley Settlement on Brush Mountain in Bell County and snakes its way north through the mountains to Baxter . Clover Fork starts on Black Mountain in Holmes Mill, near the Virginia border, and flows west in parallel with Kentucky Route 38 until it reaches Harlan . Clover Fork once flowed through downtown Harlan and merged with Martins Fork at the intersection of Kentucky Route 38 and US Route 421 until a flood control project began in 1992 diverted it through a tunnel under Little Black Mountain from which it emerges in Baxter and converges with Martins Fork . Poor Fork begins as a small stream on Pine Mountain in Letcher County near Flat Gap, Virginia . It flows southwest in parallel with Pine Mountain until it merges with the other two forks in Baxter . </P>

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