Rio Grande.

Maria Lopez is the daughter of an American mother and a Mexican father, who is the head of a band of insurgents. As a child, she was kidnapped by her father and raised south of the border to hate gringos. She begins to like them a lot better when, during an escape from some Mexican "Rurals," she crosses the border and is captured by Texas Ranger Danny O'Neil. He lets her go, and they fall in love, but their romance is interrupted when she hears that her father has been captured by Americans.