The 72-mile-long Mud River, which empties into the Guyandotte River at Barboursville in Cabell County, has its headwaters near Madison in Boone County. The Mud River, never bigger than a big creek except during times of flood, crosses into Lincoln County and flows through the communities of Mud, Spurlockville, Palermo, Sias, and Myra before reaching Hamlin, the county seat. Crossing the county line into Cabell County, the Mud continues north to Ball's Gap, then on to Milton. From Milton, the river turns west, heading for Barboursville and its confluence with the Guyandotte.

In the 19th century, trees were felled on nearby hillsides and rafted down the Mud River. Gristmills, sawmills, tanneries, and brick kilns were located along the river's banks. Sturdy covered bridges, swinging foot bridges, flatbed ferries, and willow-shaded fords carried traffic over the river. Today, some Mud Valley residents continue to farm, with tobacco and corn the chief crops.

In 1938, Congress approved construction of a flood-control reservoir on the Mud River, but there seemed to be little public interest in the project and it was never built. A flood-control dam was built on the upper Mud River in the mid-1990s, creating a 306-acre lake near Spurlockville.