If you are 62 or older, please take advantage of this. Senior lifetime passes are going up from $10 to $80 on August 28. You are better off going to the park in person, but you can also do it online, for a fee of $10.
The U.S. National Park Service will celebrate its 100th birthday on August 25th and admission for visiting over 400 parks will be waived. The Washington State park system is also waiving fees this weekend so be sure to check with the parks in your area.
This is a page about camping at national parks. Some of the most beautiful places for camping, in our country, are protected as part of the National Park system.