Short answers, pulled from the story.
The Cumberland River begins as three separate streams in the mountains of Kentucky. Martin's Fork starts near Hensley Settlement on Brush Mountain in Bell County, Clover Fork rises on Black Mountain in Holmes Mill, and Poor Fork emerges on Pine Mountain in Letcher County. All three forks converge at a single point in Baxter within Harlan County.
Thomas Walker of Virginia named the river in 1758 during his exploration. Historians do not know if he chose the name for the Duke of Cumberland or the English county. Shawnee Native Americans called the water Wasioto long before European contact arrived.
Major dams have impounded areas of both the main stem and many important tributaries including Wolf Creek Dam which created Lake Cumberland. Cordell Hull Lake forms northeast of Nashville after the river is dammed twice while Old Hickory Lake appears further downstream before the Stones River joins the flow. Cheatham Lake forms when the river is dammed again after passing through Nashville.
Harlan, Kentucky suffered severe flooding in April 1977 that destroyed most homes and businesses. This disaster led to the construction of the Martins Fork Dam for future flood control. The downtown area of Nashville received an evacuation order during late April and early May 2010 floods.
Quadrula tuberosa exists only within the Cumberland River basin as a freshwater mussel known locally as the Rough rockshell. It represents unique biodiversity found exclusively in this specific watershed. Conservation efforts focus on protecting these rare aquatic creatures from pollution and habitat loss.