The Brits have done well, financially and otherwise, with their nationally-owned galleries and museums being free.   They are a huge draw for visitors and crowding is reduced because people don't feel like they have to spend several hours in them in order to get their money's worth.   It also cuts down on lining up for tickets, which is the big nightmare at the grand galleries in Paris.  There are also donation boxes around that always seem to have a lot of coins and bills in them.

Making the national parks free for a year isn't a bad idea to draw more people and many who live in cities and forget they are out there.  How many immigrants camp?   It will be interesting to see how it works.   I'd rather see a modest capital gains tax on principal home ownership under ten years and a relatively steep one on speculation if it means that more people would spend time getting to know different parts of the country better (not to mention breaking the mentality of homes as investments).