Lingamish sums up the experience of every rural American:
"In the small town where I grew up we absorbed from infancy a loathing of the citizens of the nearly identical town down the road."
The rivalry I grew up in was between Worthington and Adrian. It goes back to battles over which town would become county seat, with some Protestant vs. Catholic animosity thrown in. Adrian's Wikipedia page actually talks about it.
A professor in college once told a story about the Masons duking it out with the Knights of Columbus in her rural Nebraska town. And by duking it out, I mean fisticuffs and destruction of property. I wonder if any of that went down in Nobles County.