Zane Grey 
Border Legion 

The story takes place in the mid 1800’s in the Idaho/Montana area. Young and attractive Joan Randall has a spat with her boyfriend, Jim Cleve. The next day she realizes that she was too harsh with him and learns he has left the area. She decides to go after him. Alone in the rough West, she happens upon an older fellow from town and he decides to help her track Jim. Unfortunately, they encounter outlaws who are lecherous and ruthless. Joan is taken captive by Jack Kells who takes her deep into a secluded canyon where his gang of bandits frequently gather. Kells keeps Joan safely away from the men for which Joan is thankful especially since the mountain of a man, Gulden has a particularly cruel reputation. Also showing up in the canyon is a young man unknown to any of the outlaws but he fits in easily with them. The man is Joan’s boyfriend, Jim Cleve. Joan and Jim keep their connection secret. Each of them aware of the danger if they are found out. (Goodreads)