If you're going to be visiting several national parks at one time, or over the course of a year, invest in one of the national parks and federal recreational lands passes. Each pass admits the card holder as well as all other persons in your vehicle (or up to three others at places that charge per person rather than per vehicle) to any national park and other designated federal recreational lands, such as U.S. Forests.
The $80 America the Beautiful Annual Pass is valid for a year from the date of purchase. To buy the pass online, visit usgs.gov; to order by phone, call 888/275-8747, ext. 1.
If you're 62 or older, you can purchase the America the Beautiful Senior Pass instead for $10. Not only does it cost less money, it is valid for a lifetime. You must, however, purchase it in person at one of the national parks or other federal recreational areas.
Those with permanent disabilities are entitled to the free America the Beautiful Access Pass. You must show documentation of your disability in order to receive the pass, and it can only be obtained in person. It is valid for a lifetime.
Volunteer 500 or more service hours in the park and you'll be eligible for the America the Beautiful Access Volunteer Pass. It is valid for one year from the date of acquisition.
All passes are non-transferable, and you need to have photo identification with you when presenting your pass. Note: The Golden Eagle, Golden Age, and Golden Access passes have been discontinued. These passes can still be used for park entrance if they are still valid according to the pass's original provisions.
For Canada parks you can purchase a Discovery Pass, which allows entrance to Canada's 27 participating national parks and national historic sites for a year, or the Annual National Parks Pass for national parks only. Purchase the pass in person when you visit the park. Individual and family passes are available. See www.pc.gc.ca for details.