"Crow Killer, The Saga of Liver-Eating Johnson," written by Raymond W. Thorp and Robert Bunker, is the true story of John Johnston (last name is alternately spelled "Johnston" and "Johnson"—the latter version was a spelling mistake made by the Union Army when he joined in 1864). The tale begins with the stark pronouncement that in May 1847, Crow Indians killed and scalped Johnston's young, pregnant wife. Johnston had been away for months on a fur trapping expedition and upon his return to their cabin finds the skeletal remains of his wife and the evidence that she had been pregnant. For many years after, Johnston is bent on killing Crow, scalping them and extracting and eating their raw livers. This explanation thus explains the title of the book. In 1972, the story was made into a major motion picture starring Robert Redford. The movie's title, "Jeremiah Johnson" uses the middle name of John Jeremiah Johnston.

The story quickly flashes back to a young twenty-year-old Johnston who arrives in St. Joseph, Missouri, to begin a career as a fur trapper. Johnston is six feet tall and 190 pounds. He has a stubble of red hair and cold, light blue eyes. Johnston buys supplies from a local supply store owner, Joe Robidoux. Robidoux sells Johnston a rifle, traps and a spirited Comanche pony. Johnston becomes the young apprentice to a seasoned trapper, John Hatcher who is the epitome of the mountain man, tall and muscular with long blond hair and heavy beard.

On one of their fur expeditions Hatcher and Johnston are attacked by Arapaho Indians, Johnston taking an arrow in the shoulder. Despite his injury, Johnston is able to take out one of the attackers and Hatcher handles the other two. Afterward, Hatcher teaches Johnston how to scalp Indians. After several years of trapping, Johnston becomes one of the most powerful and formidable mountain men, a legend in his own time. Johnston, now at 6'2" and 240 pounds allegedly kills an Indian just by slamming him to the ground. His powerful kick is deadly and feared by the Indians.

Johnston travels to the Flathead Indian camp and trades furs and other items for the daughter of the sub-chief. The girl, The Swan, becomes his wife and takes her back to his cabin. It is soon after that when Johnston returns after a fur expedition to find his wife brutally murdered. In 1848, word spreads of the despoiling of the Crow Indians by John Johnston. Crow Indians were found not only murdered but mutilated—their bodies cut below their ribs and their livers removed. Johnston's friends knew that Johnston was killing the Indians and eating their livers raw. Even Johnston's friends were unaware as to the reason he ate their livers—perhaps something vaguely related to principles. Johnston feels certain that one of the Crow he killed was the killer of his wife. He shows the murderer's scalp to his father-in-law as proof of his fulfilled vengeance.

Johnston maintains the life of a Mountain Man a fur trapper. His 'family' becomes the other Mountain Men who share the same life. Johnston estimates that he killed 400 to 500 Crow during the 25 years of his vendetta. Johnston finally makes peace with the Crow and becomes a friend to them. Later in life he has several stints as a law enforcement officer in several small towns. Towards the end of the saga, the frontier begins to get too crowded for the Crow Killer, most of his Mountain Men contemporaries are gone, the furs are becoming scarce and there are not many Indians left to kill. In the late 1890's Johnston becomes ill and dies in a Veteran's Hospital in 1900. His headstone has no mention of the Liver-Eating Crow Killer; rather, it has an abbreviated inscription attesting to his brief time with the Union Army, Company H out of Colorado.