Vets get free lifetime pass.
https://www.nps.gov/planyourvisit/veterans-and-gold-star-families-free-access.htm#onthisPage-2
“The free Military Lifetime Pass admits the veteran or the holder of the Gold Star Family voucher as well as occupants of a single, private non-commercial vehicle OR the veteran or voucher-holder and three persons (16 and older) where per person fees are charged. The passes are non-transferrable and are void if altered.”