The filming of Thunder In The Sun probably had its start years before they were movie stars with two grade school kids named Edythe Marrenner and Ira Grossel who both went to Hollywood and became Susan Hayward and Jeff Chandler. These two were really good friends going back to their childhoods in Brooklyn. So when Susan Hayward reached the top of her career with her Oscar for I Want To Live, I'm sure she wanted to make a film with Chandler. It's a pity these two couldn't have found a better one.
It's an unusual subject for a western, a wagon train of Basque immigrants from the French Pyrennees who are going to California to start their own wineries. Their most precious cargo is the vines carrying the grape seeds that have to be watered. Of course on the desert, man and animals also have to be watered. That leads to the usual situations in westerns like these.
Chandler is not your usual western hero either. He takes his pleasures where he finds them be it women or drink. Hayward has been wed to Carl Esmond the leader of the group and when he's killed by an overanxious sentry, the younger brother Jacques Bergerac is ready to take his place. And Hayward is also guarded by her formidable mother-in-law, Blanche Yurka.
Though the folks have unusual clothing for wagon train travelers, the story does have the usual wagon train situations found in westerns, climaxed by a nicely staged fight with Indians. As Bergerac says, the Indians have never faced Basques before and these people are born mountain fighters.
In two years Jeff Chandler would be gone and he never did to make another film with his good childhood friend Susan Hayward. That's a pity.