Above: Headlamps from climbers are visible on the side of Mount Rainier (Glenn Nelson photo).

Entrance fees are waived on Tuesday, Aug. 25, for all 408 National Park Service units, for Founder’s Day, celebrating the park service’s 99th birthday.

Fees also will waived on two more days in 2015 – Sept. 26 (National Public Lands Day) and Nov. 11 (Veterans Day).

The theme of celebrations across the country is 99 ways to #FindYourPark. A list of 99 suggested activities in NPS units, click here.

Most units are holding special programs, some of which are listed at the link below:

Click Here for Special NPS Birthday Programs

Yosemite National Park, for example, is partnering with REI for an interactive “village” outside the Yosemite Valley Visitor Center. Renowned alpinist Conrad Anker, one of the stars of recently released, “Meru,” will appear at the REI Village from 11 a.m. to 1 p.m. Other activities will take place from 9 a.m. to 4 p.m.

Click here to find a national park near you.