The Vintage Reader

I'm looking for a quote from Cheers, and the Internet is being naughty tonight and not yielding it up for me. Come on: I would have thought that every single line ever spoken on Cheers would be out there somewhere, but evidently not.

I don't remember the context, despite seeing the episode probably a dozen times, but Frasier is talking about some highway or another and he says something along the lines of "One wrong turn and it's hello, Tulsa!" If anyone remembers the episode and can tell me approximately what season it is (or better yet, has it on DVD and can verify the quote for me) I'd appreciate it.