Gordon Bennett, what a mishmash. This is possibly a little better than the "standard western" of lore - there is a female character with actual personality! - but with the clichéd portrayal of the Native characters (with of course the status of "good" or "bad" bestowed according to their friendliness to whites), plus the way the author kept moaning about how brave the lady was to let her husband go around trying to arrest the warmongering Native chief at risk of his own life, and how women always have to Sacrifice their menfolk thusly for the Advancement of Civilization...
...yeah. I haven't got an original publication date, but I will swear I smell World War I all over the writing. And then after the third very contrived time the warmongering chief slipped out from right under the white heroes' noses, and the book only a third done, I just gave up. :P Shame, because the characters are interesting and distinctive and likable, as long as the writer keeps his generalizations about Human Nature out of the picture.