The National Park Service will waive entrance fees for Great American Outdoors Day on Aug. 4, the anniversary of the Great American Outdoors Act.

Of the 475 sites within NPS’s purview, 106 require an entrance pass.

Pick a park. Any national park. They’ll all be free to enter on Monday, Aug. 4, one of the last fee-free dates this year. And it’s not just national parks like Acadia and Yosemite, but every site ...