Which two cities do you believe most need to be connected by an interstate, which are not currently?

I think my vote goes to Portland and Las Vegas. It makes no sense why an interstate doesn't run between those cities. It could run through Bend. It would also be the only north-south interstate in Nevada.
Answers

Bill-M

From Portland Drive South on Interstate 5. Turn left onto Interstate 210, Turn Left onto Interstate 15. Bingo - Your in Las Vegas. Freeway all the way - No traffic lights.