Hey Yosemite National Park — they say it’s your birthday! If you’re looking for a birthday souvenir 59 Illustrated National Parks is the book to get. On August 25, 2016 the National Park Service celebrates its 100th birthday by inviting the public to enter every national park in the nation free. Will there be crowds? For sure. In fact, limits are typically placed on admission so the most popular parks such as Yosemite don’t become overburdened. National Parks in California where you’ll normally have to pay but not on these free days — August 25 through August 28, 2016 — include: