The Lincoln County Feud occurred on Harts Creek in Lincoln and Logan counties in 1889-90. It was primarily caused by competition between country merchants, with alliances based on family grudges. It has been called the Lincoln County War, the Brumfield-McCoy Feud, and the Brumfield-McCoy-Adams-Hall War. A song written about the trouble was titled "The Lincoln County Crew."

The feud began when Paris Brumfield killed Boney Lucas at the West Fork of Harts Creek around 1884. Paris thereafter feuded with Lucas's father-in-law, Cain Adkins (a preacher, doctor, constable, and schoolteacher), as well as Cain's son-in-law, Green McCoy, a fiddler from Pike County, Kentucky. Meanwhile, Paris's oldest son, Al Brumfield, was making enemies over his prosperous operation of a whiskey boat and log boom in Harts. His rivals were Deputy Sheriff John W. Runyon, a timber boss, storekeeper, and saloon operator originally from Kentucky, and Ben Adams, Al Brumfield's uncle by marriage, who accused him of log theft. They reportedly hired Green McCoy and Milt Haley to kill Brumfield. Haley, a fiddler and first cousin to Runyon, had married into the Adams-Mullins family on Trace Fork.

On September 22, 1889, McCoy and Haley ambushed Al Brumfield as he and his wife rode a single horse past Thompson Branch. Brumfield was shot in the arm while his wife was shot in the jaw. Both Haley and McCoy disappeared into Kentucky but were jailed in Martin County in late October. Brumfield and a posse brought them to Hugh Dingess's home on Smoke House Fork in Logan County, where about 100 men gathered for protection against an Adams-Adkins-Runyon mob organized nearby. While there, McCoy made a confession and, at some point, he or Haley played the fiddle, either "Brownlow's Dream" or "Hell Up Coal Hollow." They were then taken to Green Shoal and—by varying accounts—cut, shot, hanged, or hit over the head with the butt end of an axe. Sometime later, local preacher Ben Walker headed a burial party which interred Milt and Green in a single grave on West Fork.

The feud ended sometime during the winter of 1890. Cain Adkins escaped by horseback to his childhood home in Wayne County, leaving his family to make their way out on a rented boat. John Runyon sold out to Al Brumfield, who became Harts' chief businessman during the 1890s. Paris Brumfield was murdered by his son Charley in 1891.