Even better, senior citizens (62+) can purchase a lifetime pass to America's national parks for just $10, which gets you into every park for free. It's a deal worth getting on top of, because the price is about to rise to $80, according to Time. The National Park Service has not announced when the price hike is going to happen, but it's coming soon. That means it's an excellent weekend to take advantage of the price because you can get in for free and it's a flat $10 if you purchase your lifetime pass on site. If you purchase it online, there's an additional $10 processing fee.
U.S. Citizens with "permanent disabilities" can get a free lifetime pass through the Parks' Access Pass program. If you're in fourth grade, you can also get a free pass for the entirety of your fourth grade school year. Additionally, current members of the U.S. Military and their families are eligible for a free annual pass.