There has been a great number of people involved in the mining and fossil fuel Industries who have greatly resented the land set aside in national parks around America. Under all the ministrations in the past these lands were sacred, set aside for the youths of all citizens of America and all visitors.
As with many areas like this it is hard to fully calculate how much it is worth. However as a businessman trump nearly sees these as areas that he and other people in business cannot use to their own profit. As such since coming to power he was appointed people who will work alongside him in stripping as many of these protections as possible.
The first complaint trump had against the national park service ( a government body that covers more than you would think) was that as well as it’s duty it it published the numbers that came to watch trump this morning and they were substantially lower than they were under Obama. He then appointed Ryan zincke who’s first moves where to double the cost of entering national parks, rescind climate policies (because Trump had run on a policy that he didn’t believe global warming existed) and forcefully relocate senior National Park superintendent- given that many of these have lived in one place too much of their career and were therefore settled most of them simply resigned rather than be moved for no reason other than to be able to remove their influence.
They went through several other National Park directors who undertook various moves the only advantage of which was to remove impediments to doing things that business wanted. The government shutdown did damage to the park as did changing the rules on e-bikes and increasing the number of of wolf cubs and bear are cubs being killed to help Hunters be able to take more animals.
Despite this astounding assault on the the wilderness within the USA hey there has been little outrage from the general public. These areas are great for for Recreation and for biodiversity and for tourism, however often the bigger issue is the environmental services that these wild areas provide. Resource extraction often pollute waters that people drink further downstream, as well as accelerate the speed that water moves into Rivers by the removal of trees which leads to very regular flash floods further downstream.
A second term for trump and Republicans would allow them to permanently damage the national park system. A complete change of direction would give national parks a chance at recovery before the system that has protected the last of of North America’s big mammals from complete extinction is destroyed entirely.