You really can't wander too far you will get arrested pretty much everywhere in this country. That ain't freedom.
Well, you can wander nude in Oregon without getting arrested. The Oregon State Supreme Court ruled that under the State's constitution, nudity is protected as "free speech". The ogf hte ruling was pretty vague though, so the only time there is no gray area, is when people are protesting. Still, to my knowlede every person who was arrested for violating local nudity ordinances who brought up that ruling has had their case dismissed.
I've heard Vermont also has a nudist friendly legal situation.