Acadia National Park – already one of the best vacation bargains around at the normal entry fee of $20 for 7 days – gets even better on Aug. 25.

That’s the day Acadia is free, in honor of the National Park Service’s 98th birthday, along with more than 100 National Park-run units that normally charge an entrance fee.

Hull’s Cove Visitor Center in Acadia National Park

Every year on Aug. 25, the National Park Service celebrates Founders Day, marking the United States as the first country in the world to create national parks.

The National Park Foundation, a non-profit chartered by Congress in 1967 to partner with the National Park Service, has set up a Web site to allow people to wish the park service “Happy Birthday”, and to make a tax-deductible gift to help support what has been called America’s best idea.

In 2016, the park service will mark its Centennial, as will Acadia. And as the park service approaches its second century, the issue of federal funding and fee structure will be a continued source of debate, according to a recent article by National Parks Traveler.

If you can’t make it up to Acadia this Monday in honor of the park service’s 98th, there are other times of the year you can gain free entry:

– Sept. 27, a Saturday this year, is National Public Lands Day
– November through April, the park’s off-season

And there are other ways to take advantage of all that Acadia has to offer for free or at discount. Check out these special federal recreation-site passes that also allow entry for passengers in the same car as the pass holder:

US citizens or permanent residents age 62 or over can get a lifetime Senior Pass for $10. NPS photo.

– $10 Senior Pass, a lifetime pass for US citizens or permanent residents age 62 or over
– $40 Acadia Annual Pass for year-round access, good for 12 months from purchase
– Free Interagency Annual Pass for active duty military personnel and their dependents and for volunteers who have provided 250 service hours on a cumulative basis
– Free lifetime Access Pass for US citizens or permanent residents with permanent disabilities

The special passes can be purchased online or at Acadia’s visitor center.

Acadia National Park annual pass, $40, is good for 12 months from purchase. NPS photo.

And if you don’t qualify for a special pass or can’t visit on a fee-free day, and want to avoid possible lines at the Acadia visitor center, you can purchase the normal $20 7-day entry pass at these other locations, according to Acadia’s web site:

– Bar Harbor Village Green, across from the main Island Explorer bus stop
– Blackwoods Campground
– Sand Beach Entrance Station
– Seawall Campground
– Thompson Island Information Center
– Ann’s Point Inn
– Appalachian Mountain Club, Echo Lake
– Bar Harbor Chamber of Commerce, Cottage Street
– Bluenose Inn
– Cadillac Mountain Gift Shop
– Jordan Pond Gift Shop
– Mt. Desert Town Office
– Southwest Harbor and Tremont Chamber of Commerce

Whether you go to Acadia on a fee-free day, with a special pass, or by paying for the normal $20-for-7-days pass, there’s no better way to celebrate the National Park Service’s birthday than by visiting one of its gems.