> the national parks are almost fully funded by the people that visit them.
Even if that were true, National parks are big, which means the additional space taken up by toll collection infrastructure at parking areas (and the staff to man them) aren't a big deal, and they present lots of needs for people to stop and buy things which creates concession opportunities.
This is significantly less true of most (but not all) local parks.
But, anyway, even National Parks funding comes mostly from appropriated funds; fees (both directly from visitors and commercial services) are on the order of a couple hundred million of the single-digit billion dollar annual parks spendibf. And even that amount actually spent doesn't meet upkeep needs; the National Parks have deferred maintenance costs on the order of four times the annual budget.
Even if that were true, National parks are big, which means the additional space taken up by toll collection infrastructure at parking areas (and the staff to man them) aren't a big deal, and they present lots of needs for people to stop and buy things which creates concession opportunities.
This is significantly less true of most (but not all) local parks.
But, anyway, even National Parks funding comes mostly from appropriated funds; fees (both directly from visitors and commercial services) are on the order of a couple hundred million of the single-digit billion dollar annual parks spendibf. And even that amount actually spent doesn't meet upkeep needs; the National Parks have deferred maintenance costs on the order of four times the annual budget.