Today marks the start of National Park Week, running April 16-24, 2011. The U.S. National Park Service sponsors various free entrance days throughout the year. This entire week just happens to be free. Details of the program, as well as a list of any activities can be seen here.

Fee waiver includes: entrance fees, commercial tour fees, and transportation entrance fees. Other fees such as reservation, camping, tours, concession and fees collected by third parties are not included unless stated otherwise.