So brave, young, and handsome / Leif Enger.

Enhanced descriptions from Syndetics:

A stunning successor to his best selling novel Peace Like a River , Leif Enger's new work is a rugged and nimble story about an aging train robber on a quest to reconcile the claims of love and judgment on his life, and the failed writer who goes with him.

In 1915 Minnesota, novelist Monte Becket has lost his sense of purpose. His only success long behind him, Monte lives simply with his wife and son. But when he befriends outlaw Glendon Hale, a new world of opportunity and experience presents itself. Glendon has spent years in obscurity, but the guilt he harbors for abandoning his wife, Blue, over two decades ago, has lured him from hiding. As the modern age marches swiftly forward, Glendon aims to travel back to his past--heading to California to seek Blue's forgiveness. Beguiled and inspired, Monte soon finds himself leaving behind his own family to embark for the unruly West with his fugitive guide. As they desperately flee from the relentless Charles Siringo, an ex-Pinkerton who's been hunting Glendon for years, Monte falls ever further from his family and the law, to be tempered by a fiery adventure from which he may never get home.