You can obtain passes for the disabled and elderly that will give you discounted admission to the National Parks and many state parks throughout the US. Go to the National Parks Service web site or the appropriate state web site to find out more and obtain the required forms:
The National parks Service web site is:
www.nps.gov
The New York State Park Service web site is:
www.nysparks.com
The Bookshare home page is:
www.bookshare.org