The Valley of Silent Men by James Oliver Curwood

Corporal Kent is wounded in the course of duty, and, since he believes he is dying, he confesses to a murder to pay back a debt of gratitude. But he recovers, and is arrested. Marette Radison who has come to live with Inspector Kedsty knows who the real killer is, and she helps Kent to escape. He hides in Kedsty's home and the next day, the inspector is found strangled with a rope of women's hair, the same way the two other men were found dead. Kent is pursued by his friend and fellow Mountie, O'Connor (so he and Marette flee. While heading for "the valley of silent men," the pair are separated, but Kent later finds Marette in the home of her father, Pierre who reveals that he is the killer. O'Connor arrives and hears the old man's deathbed confession. Kent's name is cleared and he weds Marette.