In the Spring Brake episode where the Simpsons go to Florida and kill Cap'n Jack. they get banned from the state of Florida. Then you see homer cross Florida off the map of the USA. all the other states except for Arizona and North Dakota. Homer doesn't want to go to Arizona and Bart said he's always wanted to go to North Dakota. If all the other states were crossed out, Springfield must be in Hawaii or Alaska.
Or maybe they just screwed it up.