The only connection I have with Omaha is that when I was in 6th grade we had a girl move to Seattle from there and she was placed in my class mid-year.
Everyone made fun of her accent and her obsession with the the town itself.
Nearly every one of her anecdote's began, "Back in Omaha...."
She was a big girl, in every dimension, and coming from me that says a lot-- I was the biggest in the class (height-wise; I wasn't hefty).
So as a result of never having actually visited Omaha or Nebraska in general, the impression was burned in my brain at a young age that Omaha is the home of large, loud, obnoxious people with goofy accents.