For those of us who are permanently disabled, the U.S. National Parks Service will issue a free pass to enter any National Park. This pass normally has an annual cost of $80, but for disabled people the fee is waived and they issue a lifetime pass for free. The pass is good for up to 4 adults who enter in the same vehicle as the pass holder.

http://www.nps.gov/fees_passes.htm

Have had my get in free pass for about ten years. It does not work at some places that are run by concessions: Mount Rushmore is/was one of them.

I have one. It get me half price on camping in state parks also, just as long as its not a camping cabin. And boat launching is free also with my NY pass.