OregonLive.com points out some interesting links between The Simpsons and the state of Oregon:

It's a well-known fact that The Simpsons has a lot of ties to Oregon, starting with its fictional setting, Springfield. Creator Matt Groening, who grew up in Portland, has sprinkled references to his homeland throughout the show. But where's the love for Eugene, the quintessential Oregon town that (as far as The Simpsons is concerned) has languished in Springfield's shadow? Well, it finally made the show, with a rain joke, no less, in Sunday's episode.

Here's the set-up: Carl and Lenny are acting the parts of Lewis and Clark, and as soon as they hit Oregon, it starts to rain.

"I say we give this lovely land a name," says Lenny. "How about: Eugene, Oregon?"

The show concludes with Homer watching Animal House, which was filmed in Eugene in 1978.

Which Oregon town will The Simpsons immortalize next? My personal favorite is Drain, with Boring, Riddle, Paisley and Dufur close behind.

Pretty interesting, but it still doesn't solve the mystery of where Springfield is really located...