Admission to all national parks will be free on Jan. 18 in honor of Martin Luther King, Jr. Day, the park service has announced.
The discount gives visitors a chance to skirt the $25 fee for entering sites likes the Grand Canyon in Arizona or Yellowstone in Montana, Wyoming and Idaho.
The MLK Day promotion is part of events commemorating the National Park Service's centennial. There will be 16 days in all this year in which admission is free to parks and historical sites run by the NPS.
The NPS operates several sites tied to key moments in King's life and the civil rights movement, such as King's childhood home in Atlanta and a memorial near the National Mall in Washington, but these sites are free every day. The 54-mile trail from Selma, Alabama, to the state capital in Montgomery -- along which King and thousands of protesters marched in 1965 to demand voting rights -- is also part the NPS.