THE LONG-TERM IMPACT of the presence of people may be the most damaging to federal wilderness. An estimated 860 million people hike, camp, and drive through the national forests annually, creating a severe stress on the forest ecosystems. The Forest Service predicts the numbers of visitors to the forests will rise to more than a billion each year within the next decade. Likewise, with 265 million visitors in 1997, nearly doubled since the mid-1960s, the national parks have become overwhelmed by their popularity. "Today many national parks, although still beautiful, are marred by teeming, noisy crowds in campgrounds, visitor centers, grocery stores, and restaurants, and by traffic jams on roads and even on trails," writes Richard West Sellars in Preserving Nature in the National Parks.

The "ultimate challenge" facing the national parks today is the impact of "too many people and too...