Queen of the Yukon (1940)

In this film adapted from a Jack London story, Sadie Martin (Irene Rich) runs a casino riverboat that travels the Yukon River, catering to a variety of prospectors. Despite her success, Sadie strives to keep her daughter, Helen (June Carlson), in the dark about her unsavory lifestyle. But, just as dubious businessman John Thorne (Melvin Lang) makes an offer on her boat, her daughter abruptly returns from her posh boarding school with Bob (Dave O'Brien), a friendly but gullible fiancé, in tow.