Admission to the Grand Canyon and all national parks is free this Saturday on the 25th Anniversary of National Public Lands Day. The event established, in 1994, is held on the fourth Saturday of September. This year's theme is the restoration and resilience of public lands. Interior Secretary Ryan Zinke will be visiting the Grand Canyon Saturday to lead a volunteer project to restore six cabins built in the 1930s. If the Grand Canyon isn't your thing, you can visit any national park or monument in Arizona for free Saturday. These include the Casa Grande Ruins in Coolidge, Montezuma Castle in Camp Verde, Tuzigoot in Clarkdale, Walnut Canyon in Flagstaff, or Wupatki in Flagstaff.