In celebration of the 97th anniversary of the National Park Service, all 401 national park units including Yellowstone and Grand Teton will waive entrance fees on Sunday, Aug. 25. Park officials encourage visitors and local residents to take advantage of this opportunity to explore the park and enjoy late summer activities from hiking, biking and boating, to wildlife watching and photography.

The waiver applies to entrance fees only and does not affect use fees for camping or boating. In addition, the parks will also allow free entry on Sept. 28 (National Public Lands Day) and Nov. 9-11 (Veteran’s Day Weekend).

As part of the National Park Service’s Founder’s Day, visitors are invited to share their national park experiences with others online at nps.gov/aboutus/npsbirthday.htm.