Bad Lands (1939)

A posse of nine and Sheriff Bill Cummings set out after a renegade named Apache Jack, who has murdered the wife of Lopez, one of the posse members. The others are Rayburn, Chic Lyman, Billy Sweet, Bob Mulford, Curley Tom, Eaton, Garth and an old prospector named Cluff. Apache Jack leads them into Indian country where they come across an oasis in a gully wash. They not only find water but also a natural of vein of silver. Sheriff Cummings prevents any of them from returning to town to file a mining claim. The next morning, Eaton is missing and all of the horses are gone. Then Cluff is killed in an ambush. The posse is trapped by an unseen enemy.