Sunset Serenade (1942) on Netflix

Plot summary

Vera Martin has run the Bagley Ranch since its owner died, and she expects to keep it. Instead she is told to leave: the property passes to the owner's nephew, Rodney T. Blackton, who is one year old. Gregg Jackson, who ranches next door, comes to offer sympathy. He intends to dam the river above the Bagley land, turn the water onto his own property, drive off the Bagley herd and leave behind a mortgage of $5,000. Roy rides through the country with his friends just as Sylvia Clark reaches the ranch with the child she is guardian to. Jackson tells Sylvia the land is barren, the cattle gone and the mortgage due in two weeks. Roy grows suspicious and decides to stay and help.