In the novel 'The Girl from Montana', a young girl's life is turned upside down when her brother is killed and she's left with no family. Fleeing from her home in Outlaw Territory, she embarks on a journey eastward, with only her horse and a few belongings. On her way, she meets a wealthy young man who helps her, and they part ways. However, fate brings them together again when she ends up in Pennsylvania, where she finds her mother's family. Through her struggles and adventures, she learns about God and discovers her true identity, leading her to make important decisions that will change her life forever.