FROM ITS BIRTH in 1916, the National Park Service has struggled to satisfy two missions: preserving America's special places for future generations while promoting public use and enjoyment. The National Parks System was created so that unique wilderness areas, natural wonders, and historic sites would not be despoiled. At the same time, the parks were intended for people's use—and people need roads, recreational facilities, campgrounds, and other amenities, which sometimes threaten the ecosystems and wildlife that the Park Service has sought to protect.

The beginning of the park idea

The nineteenth-century artist George Catlin, a well-known painter of the American Indians, is considered one of the earliest proponents of the concept of a national park. On a trip to the Dakotas in 1832, he saw that the pioneer movement was threatening the American Indian civilizations and...