By Brandy McDonnellA version of this story appears in Thursday's Life & Style section of The Oklahoman.'Killers of the Flower Moon' author David Grann talks Martin Scorsese film adaptation during OKC visitBefore he started working on his award-winning true-crime novel "Killers of the Flower Moon," David Grann had never seen a prairie before.Since the 2018 publication of his No.Read more on NewsOK.com