Not a strong one, this one.
It should be comic, but most of the time is not. It reminded me of French Lucky Luke comics - which are much more fun, including one called The Tenderfoot on an identical theme.
The treatment of whisky-craving, rather stupid (though pacific) Indians is fairly embarrassing and borderline sad.
The almost equally idiotic English scion - at least to start with : he has not even looked at a map where the ranch he has inherited might be located - is more excusable, but not funny enough for good laughs. Actually only his non-comic side is endearing.
The plot is weak, and the ending much too predictable.
Last, the usually honest Paladin oversells his services by describing traveling to Montana as one of the most dangerous adventures - nothing whatsoever to confirm these dire predictions later on, of the travel itself nothing said and the village itself looking exactly like a boringly quiet little place next door, so boring that locals have to play absurd jokes to get some kicks.
Main thing worth remembering : the outlandish casting of Ted de Corsia as the Indian chief.
Best quotes :
Brunswick : My father had invested money in this ranch in Montona and his share came to me.
Paladin : That state is called Montana.
Indian man, seeing Brunswick riding into the village in colonial outfit, complete with khaki shorts and helmet : Crazy clothes...