Riders of the Silences by Max Brand

The Great West prior to the century's turn abounded in legend. Stories were told of fabled gunmen whose bullets always magically found their mark of mighty stallions whose tireless gallop rivaled the speed of the wind of glorious women whose beauty stunned mind and heart. But nowhere in the vast spread of the mountain-desert country was there a greater legend told than the story of Red Pierre and the phantom gunfighter McGurk.