Rawhide river

"When Britt Cahill returned to St. Louis he stood in the shadow of the gallows. But he was desperately seeking the man who could prove him innocent of murder. All clues pointed West toward Montana. But when he boarded the Missouri River packet, Cahill was stepping into a rattler's nest of hardened renegades who had orders not to let him reach the end of the voyage alive!" p. [4] -- cover.