High Iron — E.E. Halleran

Old Hannibal Putnam was a man who just didn't know when he was licked. Not only had he set out to build a railroad on borrowed money, it had to be high up in the hills. And now there's a spy in the camp. Someone who certainly doesn't want a railroad built. Someone who would kill - and has - to stop it. That's when Hannibal decides to send for his former shooting partner, Lefty Malone. Only Lefty hasn't carried a gun in years...