I assume that the depiction of Native Americans, despite being slightly more progressive* than other westerns, is completely wrong. But I was curious as to how the movie got Native Americans wrong? Is the film's portrayal of Native American tribes close to how they actually acted? To add to that, how is its depiction of the West in the late 1800's? Did the filmmakers get western life correct, with families mostly living on isolated farms, or was life more nuanced than the film portrays?
*Progressive in that the film portrays Ethan Edwards' intense hatred of Native Americans as morally wrong and completely unheroic
The Searchers is a dramatization that was based, very loosely, on the real life story of Cynthia Ann Parker. Cynthia Parker was kidnapped by a band of Comanches when she was a young girl in the early 1830's. This same war party murdered Cynthia's parents in front of her eyes. Cynthia was the inspiration for the Natalie Wood character in The Searchers. According to Texas legend, her Uncle and Cousin searched extensively for her throughout the vast Comanche territory - these men are the inspiration for the John Wayne and Jeffrey Hunter characters. Finally, when she was already a grown woman, Cynthia Parker was found by whites, but she did not want to return to living in the white civilization. She had in fact married a leading Comanche war chief and had a son by him who grew up to be the famous chief Quannah Parker. Texas society was shocked that a white woman would choose to live with the Comanches, who had killed her parents in front of her, instead of returning to 'civilization'. Eventually Cynthia Parker was forcibly returned to the white world; but she could not adapt and she died not very long afterwards.
Hollywood movies are not intended to be accurate depictions of cultures. The screen writers took a famous story and adapted it for entertainment purposes. However, there are some general aspects to the movie that reflect the cultural clash between the Comanches and the white settlers.
Another interesting movie along similar lines is the Ron Howard film "The Missing" starring Tommy Lee Jones as a white man who chooses to abandon his family and live with the Comanches.