In honor of the anniversary of the Great American Outdoors Act, all National Parks that charge a fee will offer free admission Thursday.

That includes Washington state’s three big ones: North Cascades National Park, Olympic National Park and Mount Rainier National Park.

Throughout the country, several small historic sites overseen by the National Park Service will also be free to enter Thursday. In Washington, the Fort Vancouver National Historic Site will waive its entrance fee to the reconstructed fort site.

The Klondike Gold Rush National Historical Park in downtown Seattle (which is more of a museum about Seattle’s history than a true park), the Bainbridge Island Japanese American Exclusion Memorial and the San Juan Island National Historical Park at the southern tip of San Juan Island are all free to enter daily.

If you can’t make it out to enjoy the free entrance day Thursday, mark your calendars for the National Park Service’s next ones:

For more information, visit the National Park Service website at www.nps.gov.