Because closing down National Parks isn't in the best interests of of the general public. Keeping the National Parks open for people to enjoy is what the parks are there for. As for environmental impact, the method that is used to close tracks is environmental sabotage, The dozers do more damage in 10 minutes to the environment than what 1000 4wd's, trail bikes and horses would do in years.

We the people put you in Government and we want you to represent us, It is time that we make a stand and get our elected Government to act as our voice.