Cumberland River Tennessee, where it is joined by the Obey River and Caney Fork. Northeast of Nashville, the river is dammed twice more, forming Cordell Hull Lake and Old Hickory Lake. After flowing through Nashville and picking up the Stones River, the river is dammed to form Cheatham Lake. The river turns northwest toward Clarksville, where it is joined by the Red River, and then flows back into Kentucky at the Land Between the Lakes National Recreation Area, a section of land nestled between Lake Barkley, which is fed by the Cumberland River, and Kentucky Lake. Finally, the river flows north and
Cumberland County, Pennsylvania summer of 1863, Confederate troops marched through the Cumberland Valley, briefly occupying much of Cumberland County. In the 20th century, the suburbs of Harrisburg, Pennsylvania, the state capital, expanded extensively into eastern Cumberland County. Carlisle also developed suburbs in adjoining townships. According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.9%) is water. It has a hot-summer humid continental climate ("Dfa") and its hardiness zone is 6b except in much of the eastern portion where it is 7a. The area code is 717 with an overlay of 223. As of