You can get into every US national park for free this Saturday. Here's what you need to know.

• Saturday is National Public Lands Day, one of six days in 2021 when national park entry is free.
• The waiver doesn't cover fees for camping, boat launches, transportation, or special tours.
• Here's what else you need to know before you go.

If you're looking for an excuse to make it out to a national park, you'll get one this weekend.

That's because Saturday is National Public Lands Day, which means all $4 will be free to enter. Of the 423 national parks in the US, many are usually free to enter anyway, but some of the more popular ones typically charge an an entry fee.

This Saturday, even those parks will be free to enjoy. The fee waiver, however, does not cover amenity or user fees for things like camping, transportation, special tours, or $4.

Many national parks have seen $4. One reason for $4 is that many Americans have been eager to get outdoors more after being stuck at home for much of the pandemic. Some of the most popular parks currently require reservations to help manage the influx in visitors; keep this in mind if you want to take advantage of the waived entrance fees.

National Public Lands Day is one of six days this year with free park entrance. Most recently, admission was free on August 25, which marked the 105th birthday of the National Park Service. Earlier that month, entrance fees were waived on August 4 to commemorate the one-year anniversary of the Great American Outdoors Act. Before that, entrance was free on April 17, which was the first day of National Park Week, and on Martin Luther King Jr. Day on January 18.

If you can't make it to a park this weekend, you'll have one more chance at free admission later this year. Entrance fees will be waived on November 11 in honor of Veterans Day.

Here's $4 of parks that will waive their regular admission fees this Saturday.