That's how Montana Parks were when I was there. Free for residents, but tourists payed a pretty hefty fee.

I should also add that they were some of the cleanest, up to date, well patrolled and operated parks I've visited.

And none of them were subcontracted to private companies with minimum wage flunkies in blue smocks to empty the trash.

No private company is going to maintain the buildings and infrastructure of a park they don't own. They just collect the payments and walk away laughing.