The Interagency Annual Park cost $80 and is good for one year from the date of purchase.
What is it? Entrance Pass to National Park Service sites that charge an entrance fee.
Who is it for? The General public. Anyone may purchase the Interagency Annual Pass. The pass admits the pass holder and passengers in a non-commercial vehicle at per vehicle fee areas and pass holder + 3 adults, not to exceed 4 adults, at per person fee areas (children under 16 are admitted free).
How to get one? Go to http://store.usgs.gov/pass or at most national parks.