"As of April 2015, the National Park Senior Pass costs $10. A lifetime pass for people 62 years or older, the Senior Pass allows entry to more than 2,000 sites managed by five federal agencies.

Bureau of Land Management, US Forest Service, National US Fish & Wildlife, National Park Service and Bureau of Reclamation.

Been using it for about 9 years and my $10 lifetime pass covers me and three other people over the age of 16.