The position of Bart’s head and what we can see of the map leads me to believe the TRUE Springfield must be in the Midwest or lower Mississippi delta. This narrows the possibilities to a manageable number of plausible locations
It’s Not Oregon People.... Matt Groening Himself Once Stated That It’s An Ongoing Joke To Which Springfield Has No State. He Even Said That He Himself Has Never Decided Where Exactly It Is So That The Family Can Be Basically Near Whichever City They Need To Get To For The Episode.
It is supposed to be a joke. Whenever they are about to say in which state they live there’s always a distraction. Like in the Brazil episode and the other where it seemed like Marge was saying Ohio but ended up saying “Oh hi, Ned”. I honestly like not knowing.