From the halls of an Arkansas high school that forever changed the course of the nation’s ongoing fight for racial equality to glaciers melting at alarming rates because of climate change in Glacier National Park to the Roosevelt Arch, gateway to America’s first national park — this week I will visit public lands across the country to mark the 100th anniversary of the National Park Service. With more than 400 places that make up the most incredible park system on the planet, these natural, historical and cultural treasures show the wide range of what the National Park Service preserves, promotes and protects for future generations to enjoy.