The statue of Paul Bunyan in Brainerd was actually built specifically for the film. Evidently, Bunyan is Brainerd's most famous former denizen, and the statue is the kind of roadside attraction you find in small town America, like the World's Biggest Ball of Twine. It's the first thing Marge mentions when calling Jerry Lundegaard on the phone: Brainerd is "home of Paul Bunyan and Babe the Blue Ox."
It looks sort of creepy, though—Bunyan looks kind of like an ax murderer. In one shot, the statue is lit from below, making it look especially sinister. And, after Marge arrests Gaear, he stares out the window of the police car, looking at the Bunyan statue as they drive by. Perhaps he's remembering how he just killed Carl with an ax?
Of course, Paul Bunyan wasn't real, and thus not actually from Brainerd. Sorry to burst your blue ox-shaped bubble.