James Walker 
Rail Kings (Wells Fargo Trail Book #3) 

They would pay any price and stop at nothing to win.As an undercover agent for Wells Fargo, Zac Cobb isn’t the kind of man who goes out looking for trouble, but trouble seems to have a way of finding him. And he isn’t the kind of man to run away from trouble, even if it means putting himself in harm’s way.When Zac foils an attempt to kidnap the family of the oldest daughter of General Sydney Roberts, the President of the Denver and Rio Grande Railroad, he then must lead the threatened family to safety in Colorado despite the pursuit of a small army of hired gunmen. Once, there, Zac finds himself ensnared in the ongoing deadly railroad war between the Chicago Pacific and the Denver and Rio Grande Railroads. But when Elizabeth Robert decides she’s in love with Zac, his personal danger is compounded.Powerful lords of the steam engine fight for control of the narrow passage through the Rockies. The railroads will pay any price and stop at nothing to win. It takes a man who can’t be bought to restore right from wrong, and Zac Cobb is such a man.