Visitors must pick up tickets for the free tours of the Discovery and Mammoth Passage caves, which are being given April 21-29.
Park Superintendent Patrick Reed says outdoor activities benefit not only physical and mental health, but “it’s just plain fun.”
In addition to the free cave tours, the park has scheduled special walks and other activities on April 21 and Junior Ranger Day on April 28. A full listing of activities is available on the park’s website.
Source: Washington Post