Trail of the Long Riders — Lee Martin

Jess Darringer's younger brother, Sam, rides in with grim news: the woman Jess had loved and left behind was murdered by five ruthless thugs. Jess is driven to avenge her death - but before he can, he has to find the killers and enough evidence to prove them guilty. His best lead is a receipt made out to a member of the Colby ranching clan. When Jess and Sam sign on as gunhands with Colby, they know they're asking for trouble.