Swamp Women (1956)

Starring Marie Windsor, Carole Mathews, Beverly Garland, Touch Connors, Susan Cummings
Directed by Roger Corman
(actor & director credits courtesy IMDB.com)

A policewoman poses as an inmate in a women's prison in order to stage a jailbreak, so her new cellmates can lead her to the location of a cache of stolen diamonds, hidden in a Louisiana swamp.

This is by no means a great film, but it is very watchable, and the female stars make it believable and interesting, even if their characters are somewhat broadly drawn.  It's a shame that the only way to see it is in murky public domain prints that don't showcase the Louisiana scenery very well.  Another of Roger Corman's many low-budget productions, and one without a sci-fi premise or horrific monster to pull in much of an audience, it nevertheless worked for me, although the female gang trusts Mathews a bit too easily without ever really suspecting her police trap.  Despite that, the action is pretty well staged, the screenplay isn't bad, (written by David Stern, better known for creating the character of Francis The Talking Mule), and the ladies entertain.