The Duchess and the Dirtwater Fox (1976)

It's 1882 on the Barbary Coast. Charlie Malloy aka the Dirtwater Fox, makes his living cheating at cards. His latest venture however is stealing $40,000 from a bunch of outlaws. Bluebird, a saloon performer and prostitute, wants an easy life. When a Mormon, Josiah Widdicombe, comes to town, Bluebird has the idea that being the seventh wife of a Mormon would be a good life - she only has to work once every seven days. She steals Malloy's bag with the money, unaware of the amount inside. She only wants enough to buy a dress to masquerade as a duchess for Widdicombe. The ruse works. On Bluebird's way to Salt Lake City, Malloy catches up with her. Although Bluebird still has every intention of becoming a Mormon wife, the two decide to partner on the scheme of Mormon riches. All the while, the outlaws are on their tail after their $40,000.