The high graders - Louis L'Amour

The story was that Eli Patterson had died in a gunfight, but Mike Shevlin knew it
couldn't be true: the man who'd been like a father to him had been a Quaker. But
when Shevlin rides back to Rafter Crossing to uncover the truth, he finds that the
quiet ranching community has become a booming mining town. Newfound wealth has not
made Rafter a peaceful place, however, and the smell of fear and greed is thick in
the air. As Mike Shevlin tries to unravel the mystery of Patterson's death, he is
led deeper and deeper into a conspiracy that controls not only the fate of Rafter
Crossing but the heart of a beautiful but tormented young woman-and Shevlin's own
destiny.