Sally M. Walker's degree in geology and interest in history led her to the story of the Cherry Mine disaster. She is the award-winning author of more than fifty books for children, including Boundaries: How the Mason-Dixon Line Settled a Family Feud and Divided a Nation; The Sinking of the Sultana: A Civil War Story of Imprisonment, Greed, and a Doomed Journey Home; and Champion: The Comeback Tale of the American Chestnut Tree, an Orbis Pictus Honor Book. Sally Walker lives in Illinois.