Entrance fees will be waived at all U.S. national park sites this Saturday and Sunday , April 19-20 , to kick off National Park Week , which runs through April 27 . April 19 - 27 is National Park Week in the U.S. All parks are free to enter Saturday and Sunday , April 19 - 27 . Entry and concession fees still apply . What 's the best national park in the world ? Take your photos .
April 19 - 27 is National Park Week in the U.S. All parks are free to enter Saturday and Sunday , April 19 - 27 . Entry and concession fees still apply . What 's the best national park in the world ? Take your photos .