By Michael Lanza
When the National Park Service turns 100 on Aug. 25, it will mark not just the diamond anniversary of what writer and historian Wallace Stegner famously called “the best idea we ever had”—it marks the evolution and growth of that idea from a handful of parks created in the early days to a system in many ways without parallel, that protects 52 million acres of mountain ranges, canyons, rivers, deserts, prairies, caves, islands, bays, fjords, badlands, natural arches, and seashores in 59 parks. Without that protection, these places that draw visitors from around the world would otherwise almost certainly have been exploited and destroyed.