This is a Republic Studios shot at an A picture. The problem is that it is still Republic, after all. The film is in color, but it's "Trucolor", which is a two color process that makes the great outdoors look very odd. (The movie was clearly shot in the winter -- which makes the fact that the process really does not show green less of a liability. The blue shows up as a very cold blue) And when it is time for a big sweeping scene that's beyond this film's budget, the movie suddenly changes to black and white for a minute.
But the reason for watching is seeing Walter Brennan in full-bore villain mode. And he plays the character as that mean old evil reprobate we all know in our lives, and he is scary good at it. The character resembles his villain in "My Darling Clementine", but he has more film time to be just plain awful, and he makes the most of it. It is bravura acting, but it is not the least hammy or corny. The man won his Academy Awards for a reason.
Plot? Stranger with unclear motives takes on a corrupt town. No surprises on how this develops, though one thinks the Walter Brennan character in real life would have made prompt mincemeat of the stalwart hero, and purchased himself a few more local politicians.