Friday At The Movies - Breakheart Pass - 1975

Breakheart Pass is an American 1975 western adventure film that stars Charles Bronson, Ben Johnson, Richard Crenna, and Jill Ireland. The movie was based on the novel by Alistair MacLean of the same title, and was filmed in north central Idaho.

In the 1870s, residents of the garrison at the Fort Humboldt Army outpost are supposedly suffering from a diphtheria epidemic. A train is heading towards the fort filled with reinforcements and medical supplies. There are also civilian passengers on the train -- Nevada governor Fairchild and his mistress Marica (Jill Ireland), among others.

The train stops briefly in Myrtle, where it takes on board a local lawman and his prisoner, John Deakin (Charles Bronson), a notorious outlaw who was identified via a picture in a newspaper article. However, Deakin is actually an undercover federal agent along with his partner, the Reverend, and he discovers en route that there is no epidemic at the outpost and the "epidemic" is actually a conspiracy between a group of killers and a tribe of Indians.Source.