Nice idea but, I can't see it working.
It's like the old 'let's screw the gas companies by not buying gas nationwide for a day' theory.
People will still go on vacation to Colorado. And less RVers will make everything less crowded and more appealing to other vacationers.
Which will probably attract more people to Colorado.
RVers who enjoy Colorado will continue to visit, in spite of your personal vendetta or views.
Maybe all non-residents should stay off the Pennsylvania highways. It would make my local driving much easier. :)
