Hellgate

After the Civil War, ranch owner Gil Hanley (Sterling Hayden) helps a stranger in desperate need of medical attention. Soon he is questioned by Union soldiers about the stranger, who turns out to be an ex-Confederate soldier. Hanley, also an ex-Confederate, is unjustly convicted as a conspirator and sentenced to life in a brutal desert prison in New Mexico. After battling his tough cellmate and a sadistic guard (Ward Bond), Hanley tries to stop a plague from overwhelming the prison.