The film made clear that Roan was Mollie Burkhart’s first husband, who struggled with alcoholism and “melancholy." During the Osage Reign of Terror , he was murdered by a man hired by Ernest Burkhart, Mollie's second husband. In real life, Roan married Mollie Kyle when he was 15 years old during a short break from his time at Carlisle Indian Industrial School in Pennsylvania.
Roan's great-granddaughter Margo Gray said her family didn’t talk about him much because of his alcoholism, so she turned to archives from Carlisle to learn more about his life. When Gray was unable to answer a question from Leonardo DiCaprio, who played Ernest Burkart in the film, about what happened to Roan's land, she researched official documents from the 1920s. In an interview with the Tulsa World, Gray shared what she learned as she pieced together details about her great-grandfather's life.
Henry Roan’s first marriage Gray thought Henry and Mollie were cousins until David Grann approached her while writing his book "Killers of the Flower Moon" and told her they were not cousins by blood and were actually married in a traditional Osage wedding. In the film adaptation of Grann's book, Ernest makes a reference about “sky people" in a scene with Mollie. In studying his role, DiCaprio sat down with Gray and asked her about traditional Osage marriage.
On a piece of paper, she drew a line with 29 tick marks on it. Above the line she wrote “sky,” and below the line she wrote “earth.” She.