Completely Random

This thought just popped into my head. It's kind of a trivia question, I guess, and I'd be curious to know the answer.

What is the fewest number of states I would have to visit so that in a list of states including states that I visited and states bordering the ones I visited, I cover all 48 continental US States? (Obviously Hawaii and Alaska represent two states you would be required to visit, so we don't need to count them.)